Download 2 Mock Observation Plan - Cosmos

Athena
MOCK
OBSERVATION
ASST
PLAN
Title
:
Athena: Mock Observing Plan
Prepared by
:
Jan-Willem den Herder with inputs from the
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Date
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:
Date
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PA agreed by :
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Authorised by :
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:
Athena Science Study Team, the
Athena science working groups, Jelle de
Plaa, Arne Rau, Francois Pajot
Checked by
Distribution
Athena Science Study Team
Massimo Cappi
Thomas Reiprich
Mark Ayre
Dave Lumb
Ivo Fereira
Arne Rau
Jelle de Plaa
Francois Pajot
Jean-Michel Mesagner
15 September 2015
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Table of contents
Abbreviations and acronyms ....................................................................................................... 3
Applicable Documents ................................................................................................................. 3
Reference Documents ................................................................................................................. 3
Document changes...................................................................................................................... 4
1
Introduction ......................................................................................................................... 6
2
Mock Observation Plan .......................................................................................................... 8
3
Summary ............................................................................................................................ 14
App A.
Mock Observation Plan: list of entries ........................................................................... 18
App B.
Overview of changes in the MOP ................................................................................... 20
App C.
Source intensities of GRBs ............................................................................................ 23
App D.
count rate estimates .................................................................................................... 24
In order to update the table, click right on a table item and select “Update Field” followed by “Update entire
table”. Delete this text of course.
Athena
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Abbreviations and acronyms
ASIE
Athena Science Impact Exercise
MOP
Mock Observing Plan
TBD
To be Determined
TOO
Target of Opportunity
WFI
Wide Field Imager
XIFU
X-ray Integral Field Unit
Applicable Documents
[AD#]
Doc. Reference
Issue
Title
[AD1]
Strawman_obsplan_athena
V3.0
Excel table with mock observation plan
Reference Documents
[RD#]
Doc. Reference
Issue
Title
[RD1]
2013arXiv1306.2307N
June 2013
The Hot and Energetic Universe: A White Paper
presenting the science theme motivating the
Athena+ mission and all references to the
supporting white papers
[RD2]
n/a
April 2014
Athena: the Advanced Telescope for High Energy
[RD3]
SRE-S/ATH/2015/01
Version 1.4
Athena Science Requirements Document
[RD4]
ASIE_final.pdf
15 May 2015
Athena Science Impact Exercise
[RD5]
n/a
Draft v1.0, 15
Athena X-ray Stray Light Impact
Astrophysics (mission proposal to ESA)
June 2016
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Document changes
Version
Page
changes
0.1
All
Initial version
0.3
Updated tables
Further information from the various working groups was collected.
Key input has been:
-
additional 18 50 ks observations on nearby clusters to map
the background
1.0
Updated
update onb SNR observations
See change log in excel file for changes:
corresponding
-
harmonized inputs
excel table
-
added fluxes in 2-10 keV range for relevant sources
-
added a few plots with distribution of sources over the sky
-
included stellar end points (overlooked in previous versions)
-
started to match targets to numbered science goals and not
only to white paper
1.1
1.3
8,9
-
updated plots
-
added appendix with source intensities of GRBs
Version 1.2 was skipped to be able to use the same version number
for this document and for the corresponding excel table. Changes
include:
-
introduced a new section 2 with a summary of science goals
and re-numbered the next sections
-
added 25 Ms to the core program for discovery space of a
mission in 2028
-
implemented the new split between ‘accretion physics’ which
is part of the energetic universe together with Sgr A* and
‘end points of stellar evolution’ which remain part of the
observatory science
-
added the average source intensity and allow for checking of
total number of observations above certain average source
intensity per instrument
-
added unique reference to science goals (which are not
identical to the science goals of the SciRD but are a split
between the different topics.
And changes in the MOP due to changes in the Science
Requirements:
-
large scale turbulence in clusters (1.1.c) will be determined
for 10 regular and 10 irregular clusters. The 10 regular can
be the same sample as needed for the metl distribution in
the core of 12 clusters (1.2.a)
-
The AGN ripples are now for 25 clusters but with a longer
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changes
exposure time
-
The radio galaxy energy needs 90 systems in order to cover
the full luminosity ranges and source size ranges
2.0
All
Following the Athena Science Impact Exercise (see RDx) the science
requirements were updated. Especially the sample sizes were
harmonized and more clearly specified. This resulted for the Athena
as proposed mission in an updated Mock Observing Plan (version
2.0). in addition some further refinements were added such as
source size and countrates.
3.0
Major changes included:
-
completion of the count rate estimates
-
revised survey strategy taking into account the fact that
significant more time is needed to compensate for the
expected lack of a separate straylight baffle
-
increase of the available time for observations not
mandatory to meet the core science objectives. A major
change is to use the survey for the cluster entropy (9 Ms)
also for the survey. This requires proper handling of the data
rights in the SMP as each observation has multiple usage.
-
Updated the justification for count rate estimates including
specification of total data rates for a given observation
-
Included a fiueld indicating (tentatively) whether or not a
observation is background sensitive
Relevant changes are marked in red (will be changed to black with
the next version)
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Introduction
At the time of the preparations of the Athena mission proposal (see RD2) a mock observation plan (version
1.1) was put together and it was verified that in a reasonable mission life time (5 years) the science could be
completed with the proposed mission. It should be noted that this assessment was carried out for the
baseline mission configuration as given in the mission proposal:

angular resolution: 5 arcsec

effective area at 1 keV of the optics of 2.1 m2

vignetting corresponding to 3 mm rib spacing

Field of view of the WFI 40 x 40 arcmin

Field of view and resolution of the X-IFU 5 of arcmin (diameter) and 2.5 eV at 6 keV
Following the white paper and the mission proposal two major changes have been implemented in different
versions of the MOP:

as part of the comparison between the CDF configuration with an area of 1.4 m 2 and the mission as
proposed (2 m2) the science requirements were updated and re-grouped. The MOP has been updated
accordingly (version 1.4) but this version has not been distributed. This activity was carried out by
the end of 2014 but only presented at the ASST meeting.

Following the request of the ESA executive this exercise was repeated in a more rigorous way under
the name of the Athena Science Impact Exercise (ASIE, ref [RD4]) where the differences between
the two configurations were more precisely defined (e.g. same rib spacing for both cases and
detailed responses were prepared). Parallel to this exercise the team also updated the science
requirements and further refined some of the science objectives (unfortunately this makes it harder
to follow the evolution of the MOP as the subtotals are not really comparable). In addition the
needed sample sizes were reviewed and updated to be more homogenous (10 objects for a bin in the
data space, 25 objects to understand an distribution). The corresponding MOP which was used for
the ASIE exercise is version 1.7. As not all observing details were finalized at that stage the
reference version for the ASIE exercise is version 2.0 (minor differences exist with version 1.7 but
these do not affect the conclusions of the ASIE exercise).

It should be noted, however, that following the review by ESA of the ASIE report, additional changes
have been requested which were not yet been implemented in version 2.0. Some of the sample sizes
will be cross-checked as the samples in version 2.0 are not fully consistent. More importantly the
survey strategy was modified from 4x1Ms + 3x700 ks + 9x450 ks + 230x80ks into 4x1Ms + 3x700
ks+10X600ks+299*80ks to compensate for the lack of a separate straylight baffle for the optics. In
addition wide field imaging observations for some specific science goals (90 100 ks observations for
the cluster entropy (R-SCI-OBJ-121) and 8 for bright local AGN (R-SCIOBJ-241) can also serve as
part of the wide survey of 299 x80 ks. Hence 118 observations of the wide field survey have been
classified as B (not mandatory for the core science). This had a secondary possitve effect that the
fraction of observation time mandatory to meet the core science objectives reduced from 80% to
74% (in line with the recommendation of the Astronomy Working Group) leaving a good part for
discovery science and observatory science.
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In parallel to these major changes we have also added some information to the MOP including source
intensity, source size, TM rates etc.
It is also obvious that the actual observing plan of Athena, as will be decided by the time of the launch by
the time allocation committee, will differ from the current plan. Nevertheless the current plan can be used for
the purpose of mission design.
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Mock Observation Plan
In this section we summarize the science goals as given in [RD3] and the required observations as given in
the straw man observation plan [AD1]. For the different science objectives a representative set of
observations is listed in the MOP. The relevant information includes the coordinates or the sources, the
instrument, the total required observing time and a reference to the science goals. In Table 2-1 the
corresponding information is summarized. In this table we neglect that a number of sources is listed twice for
different science goals. However, this effect is modest (2.2 Ms in total). For reference the evolution of the
observing times between the mission proposal and version 2.0 is given in appendix B.
To help the reader to digest the richness of the observation plan, but also to see many interrelations, some
general comments can be made:

wide field survey: This survey is optimized on different depths and covers 52,7 deg2 to a depth of 7.2
10-17 erg/cm2/s corresponding to 299 pointings of 80 ks with the WFI combined with 2.4 deg 2 to a
depth of 2.4 10-17 erg/cm2/s corresponding to 3 observations of 700 ks and 10 of 600 ks
supplemented by 1 deg 2 very deep survey (4 x 1 Ms). The integration times and number of
observations account for the higher X-ray straylight than was originally assumed at the time of the
mission proposal. This survey is multi purpose and covers SCIOBJ-111, 211, 221 and 224. The fields
which are selected include the COSMOS field, the Extended CDFS the XXL Northern (LSS) field,
ELAIDS-S1, DEEP2-23h, the North Ecliptic pole and the XXL Southern (BCS) field. At time of the
launch different fields might be selected but the number of observations will not be random over the
sky.

Wide field images for selected science objectives: some of the Wide Field Images for selected science
objectives will also be used for the survey. For these (and other) observations the science
management plan should address the data rights (which can be shared between different groups).
The relevant science objectives are the ‘cluster entropy evolution’ (R-SCIOBJ-121) and ‘AGN
reverberation mapping’ (R-SCIOBJ-241).

GRBs and AGNs as backlight for WHIM: Detection of the WHIM can de done against bright AGNs or
against bright GRBs provided that, following an external trigger, the X-IFU can observe the afterglow
fast enough that the GRB is sufficiently bright (mCrab level). In addition, some extra measurements
are included based on our current knowledge (including the measurement of the correlation function
in the COSMOS field). It should be noted, however, that not all these observations are required to
achieve the science objective (but the science can clearly benefit from these measurements). Clearly
this follow up of the GRBs also requires a fair Field of Regard as the total number of expected
GRBs/year is limited). About a third of the GRBs will be at high redshift (z>7) allowing the study of
the formation of the earliest stars (POP III) (different SCIOBJ 261). On top of that for selected
detections with GRBs, extended observations to measure the WHIM in emission are also included
(SCI-OBJ 242).

Target of Opportunities: Target of opportunity obervations are critical to the Athena science case. As
such there is a well defined science requirements (4 hours after an external trigger Athena should be
on target and able to observe the events with the X-IFU). The relevant ToOs are high redshift GRBs,
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other GRBs as backlight for the WHIM, TDE and supernovae. With a total of about 2 ToOs per month
it is estimated that the science goals of the mission can be achieved. In reality the number could be
higher if this is scientifically justified (and may then go at the expense of additional consuma bles and
hence total mission duration)

Collect statistical relevant sample of a class of objects: Many of the science goals are not achieved
by single observations but require a sufficiently dense sample of sources grouped in relevant
parameters (luminosity, size, redshift). As reference we assume a 5 detection per bin. This is
justified in the SciRD [RD 3]. In other cases a class of events should be collected which has been set
at 25 objects. This explains, for example the rather large programs for determining the evolution of
the injection of entropy for clusters and the evolution of metal production in clusters (4 redshift bins
and 3 mass bins result each already in 12 Ms).

Background fields: limited time has been reserved for a deep exposure for a background field of the
WFI and of the X-IFU. In the current plan we took one single 1 Ms observation for each of the
instruments, corresponding also to the longest and deepest observations planned for these
instruments.

Observatory science: in the current plan science which is not part of the science objectives for the
Hot and Energetic Universe, but which can already be defined in detail, is listed as observatory
science. This helps in defining an optimal observing strategy and distribution of the sources over the
sky.

Discovery science: for a mission to be launched in more than a decade in the future it is appropriate
to reserve time for science which we cannot currently imagine. This is called discovery science.
Assuming all observations are carried out without multiple use of a given pointing, this time is
limited to 7.5 Ms which is too low. Taking into account the multiple use of Wide Field Images for
additional science objectives, this fraction can be increased to 19.5 Ms for a 5 year mission,
neglecting specific sources which serve more than 1 science objective (3 Ms in total). Taking into
account the this optimization, 74% of the observing time is required to perform the observations
mandatory for the core science and 26% for observatory and discovery time. Clearly this does not
exclude that in the future time allocation committees will assign more time to this category and less
to other areas.

Calibration time: the total estimated calibration time is 5% (6 Ms for a 5 year mission). Of this about
half can be performed when the other instrument is observing (e.g. variations in particle
background) and the other half will required dedicated pointings of calibration sources (e.g. CTI or
contamination)
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Overview of Mock Observation plan (sub-totals are given in orange fields). Instrument, sample
size and the total observing time is listed. In the last column we list the mandatory observing
time taking into account multiple usage of relevant observations (in the survey) or secondary
goals for a given science objective
Science objective
survey
Hot Universe
R-SCIOBJ-111
First groups
R-SCIOBJ-112
Cluster bulk
motions and
turbulence
R-SCIOBJ-121
Cluster entropy
profile evolution
R-SCIOBJ-122
Cluster chemical
evolution
R-SCIOBJ-131
Physics of cluster
feedback
R-SCIOBJ-132
Feedback induced
cluster ripples
R-SCIOBJ-133
Heating/cooling
balance in cluster
feedback
R-SCIOBJ-134
Shock speeds of
radio lobes in
clusters
R-SCIOBJ-141
Missing baryons
R-SCIOBJ-142
WHIM in emission
Short description
large area
Instru
ment
WFI
Sample size
modest area
deep observations
WFI
WFI
299 x 80 ks but 98
observed as part of other
science objectives (see
text)
3 x 700 ks + 10 x 600 ks
4 x 1 Ms
25 galaxy groups with gas
temperature at z>2 to investigate
L-T relation
Kinetic energy dissipated from
gravitational assembly in 10
regular & 10 irregular galaxy
clusters in the nearby Universe
Cosmic history of the injection of
entropy in cluster hot gas at
0<z<2. Investigate 10 clusters in
each of 4 redshift bins and 3 mass
bins (total 120 clusters)
Metal production and dispersal in
cluster hot gas out to z=2. Observe
10 local clusters and 10 clusters
per redshift bin per mass bin out to
z~2. Total 100 clusters.
Bulk motions in 25 cluster cores
with AGN, 10 of them mapped in
detail to explore microphysics
WFI
50% of wide survey
X-IFU
Mosaic of 10 irregular
clusters (regular clusters
from 122)
WFI
Detection of ripples in cluster gas
created by AGN jet activity, in a
sample of 25 clusters
Heating-cooling balance in hot gas
of 10 cluster cooling cores
MOP
total
MOP
mandatory
23,92
16,08
8,10
4,00
36,02
8,10
4,00
28,18
survey
survey
5,00
5,00
30 regular clusters
nearby and 90 clusters
(100 ks each) for z>0.5
12,00
12,00
X-IFU
30 regular clusters
nearby and 90 clusters
(100 ks each) for z>0.5
12,00
12,00
X-IFU
3,25
3,25
WFI
25 cluster cores and 10
cluster outskirts (4
observations each), 10
additional specified but
not core science
25 clusters
1,25
1,25
X-IFU
10 clusters
0,50
0,50
Shock speeds of expanding radio
lobes in 10 clusters around radio
galaxies for 2 redshift and 2 radio
power bins
Detect 200 WHIM filaments in
absorption, 150 towards BL Lacs
and 50 towards bright GRB
afterglows. Determine metal
abundances from emission lines in
targeted regions
WFI
40 clusters in total
(originally 60 were
proposed
2,00
2,00
X-IFU
Cosmos field mapping
2,00
0,00
Bridges sculpture
1,80
1,20
25 AGN
5,26
5,26
Detect emission of WHIM filaments
associated with systems detected
in absorption detected against 15
GRB afterglows
subtotal Hot Universe
X-IFU
50 GRBs (+follow up)
15 systems from R-SCIOBJ-141, 200 ks each
2,60
3,00
2,50
3,00
50,66
47,96
sum of survey
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Energetic Universe
R-SCIOBJ-211
High redshift
SMBH
R-SCIOBJ-221
Complete AGN
census
R-SCIOBJ-222
Census of AGN
outflows at
z=1-4
R-SCIOBJ-223
Mechanical
energy of AGN
outflows at
z=1-7
R-SCIOBJ-224
Ultra fast
outflows at
z=1-4
R-SCIOBJ-231
AGN outflows
in the local
Universe
R-SCIOBJ-232
Feedback in
local AGN and
star forming
regions
R-SCIOBJ-241
AGN
reverberation
mapping
R-SCIOBJ-242
AGN spin
census
R-SCIOBJ-251
GBH and NS
spins and
winds
R-SCIOBJ-252
ULXs and
SgrA*
R-SCIOBJ-261
High redshift
GRBs
R-SCIOBJ-262
TDE
Detect 10 AGN with 1043.0 < Lx<1043.5
erg/s at z=6-8 and 10 AGN with1044.0
< Lx<1044.5 erg/s at z=8-10. Constrain
SMBH seeds.
Spectral characterization of at least
10 Compton-Thick AGN with
1044.4<Lx<1044.9 erg/s per unit z at
z~3. Map obscured AGN/galaxy coevolution.
Detect at least 10 warm absorbers in
AGN with 1044<Lx<1044.5 at z=1-4
WFI
Wide and intermediate
survey
Survey
survey
WFI
Deep survey
Survey
survey
WFI
Wide survey
Survey
survey
Measure the mechanical energy of
outflows in luminous AGN at z=1-3,
10 per 3 luminosity bins and per 2
redshift bin of z=1 .
X-IFU
60 observations
3,20
3,20
Frequency and mechanical energy of
UFOs at z=1-4
WFI
Wide survey
Survey
survey
Wind energetics in 25 nearby AGN out
of 70. Wind launch physics from time
resolved spectroscopy of 10 AGN.
X-IFU
70 observations of 50 ks
+
3,50
,50
1,00
1,00
Gas, metal and energy output from
AGN and Starbursts in 25 (U)LIRGs
with a variety of AGN/Starburst ratios
X-IFU
10 AGNs of 10x10 ks
observations each,
spread over time
1,69
1,69
Reverberation mapping of 8 bright
local AGN with established lags.
WFI
Only 8 sources known
1,70
1,70
Spin distribution (histogram) of 30
nearby SMBH
X-IFU
42 objects to get 30
objects
3,72
3,72
WFI
10 GBH and 10 NS with
WFI (X-IFU feasible but
takes more time)
2,00
2,00
X-IFU
2 x 10 x 2 ks
0,40
0,40
X-IFU
30 sources
1,50
1,50
and monitor of the SgrA*
Probe ISM of z>7 galaxies by ToO
observations of 25 GRB afterglows
X-IFU
1 observation
25 GRBs with 50 ks
within 4 hours
0,15
1,25
0,15
1,25
Probe 10 TDEs by ToO observations.
X-IFU
10 TDE (X-IFU) + follow
up (WFI)
1.20
1,00
21,31
21.11
a) Measure spins of 10 Galactic BHs
and 10 NS through various methods
and probe their accretion geometry
and jet properties through
reverberation mapping.
(b) Measure winds in the same 10
Galactic BHs and 10 NS.
Accretion properties of 3 luminosity
bins of 10 ULXs
subtotal energetic Universe
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Observatory science
R-SCIOBJ-311
Auroral and exosphere X-ray
Planetary Xemissions of solar system bodies
ray
(planets and moons) and cometary
Spectroscopy
tails & their interaction with Solar
Wind.
R-SCIOBJ-312
Effects of stellar magnetic activity of 6
Stellar activity
exo-planets through repeated
in exo-planet
observations through their orbits
systems
R-SCIOBJ-322
Wind interactions in binaries through
Colliding winds phase-resolved spectroscopy in 10
in binaries
massive binaries.
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WFI
X-IFU
12 solar system bodies
including comets
0,64
X-IFU
6 known objects, at time
of mission it might be
more
0,95
X-IFU
WFI
13 objects (10 X-IFU, 3
WFI)
1,80
R-SCIOBJ-323
Magneticspheri
c accretion in
low mass
binaries
Magnetospheric phenomena and/or
accretion in nearby field M Stars, latetype PMS stars and BDs, and
magnetospheric accretion phenomena
and circumstellar disk interactions in
YSOs in selected nearby SFRs.
WFI,
X-IFU
Magnetospheric accretion
in 18 young low-mass
stars and brown dwarfs
1,04
R-SCIOBJ-324
Magnetic
activity in
ultra-cool
dwars
Magnetic activity in ultra-cool dwarf
stars
X-IFU
Observe sample of 4
objects
0,17
R-SCIOBJ-325
Mass loss in
massive stars
Characterize the mass-loss and winds
in a sample of early type stars and in
HMXBs.
X-IFU
WFI
8 objects to characterize
winds
0,61
X-IFU
WFI
30 objects
1,57
7 LMBXs, 2 interesting
milliesecond pulsars will
be done by Nicer and are
not included
10 objects selected
0,45
Measure the X-ray spectra of selected
OB associations (each containing at
least 10 massive stars) in 3 different
Local Group galaxies with different
metallicities.
R-SCIOBJ-331
EOS of ultradense matter
Equation of state of dense matter from
observations of LMXBs
WFI
R-SCIOBJ-333
Masses of
accreting
white dwarfs
R-SCIOBJ-334
magnetars
S-SCIOBJ-335
PWN
Determine M/R ratio of accreting white
dwarfs
WFI,
X-IFU
Characterize geometry of magnetars
and XDINs
Constrain particle acceleration by the
study of PWN
WFI
X-IFU
WFI
X-IFU
10 systems selected
0,50
7 objects
0,80
S-SCIOBJ-336
Novae
Observe 3 nova going off during
Athena mission
X-IFU
10 observed with 6 x 5
ks each
0,30
10 plenatary nebulae
0,38
and 10 planetary nebula
S-SCIOBJ-337
double
degenerate
binaries
R-SCIOBJ-338
SN
R-SCIOBJ-341
Chemistry of
cold ISM
R-SCIOBJ-342
0,68
Observe double degenerate systems
and on type 1A supernova at distance
< 25 Mpc
X-IFU
9 systems
0,39
BH birth through 10 SN
X-IFU
10 SN
0,50
Chemical composition of cold ISM
through absorption spectroscopy
X-IFU
WFI
8 objects for 341 and
342
0,57
Dust models and particle distribution
X-IFU
3 objects for 342 and
0,09
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Dust
scattering
haloes
R-SCIOBJ-343
Physics of the
warm and hot
ISM
R-SCIOBJ-344
Mapping of
SNR
R-SCIOBJ-351
SgrA*
Facility time
R-SCIOBJ-399
Discovery
science
calibrations
background
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343
Characterize warm and hot ISM in the
Galaxy and nearby galaxies
X-IFU
3 objects only for 343
0,60
3D mapping of SNR from SN1a and
core-collapse SN
X-IFU
Snap shots of distinct
features in 8 SNR
1.00
Characterization of the quiescent
diffuse emission from SgrA*, the nonthermal flares and the X-ray reflection
nebulae surrounding the Galactic
Centre
WFI
5 observations to map
environment
0,25
13,28
13,28
7,50
19,70)
3,34
3,34
2,00
2,00
total
134,12
133,97
MOP without duplications)
5 year mission (85%) [Ms]
131,19
134,00
134,00
0,53
0,58
Athena should be able to respond to
scientific challenges triggered by new
developments, including new multiwavelength or other messenger
observations
5% of which half is when instrument is
not in the focus
observatory + discovery +
background [%]
X-IFU observing fraction
X-IFU
WFI
Time which is not yet
assigned and together
with the observatory
science this is not
required to meet the
core science goals as
defined in the proposal
17%
26%
The MOP allows making various selections that help to define the mission requirements. For example one can
determine the total mission duration mandatory for the core science, the distribution of the sources over the
sky, the division in observing time between the XIFU and the WFI. As detailed information is given about all
known source positions, duplications in the observing plan can be avoided as well. In the current excel sheet
these sources are included but a field is added to indicate if the source is already observed as part of another
program.
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Summary
Based on this mock observing plan the following conclusions can be drawn:
-
The total observing time mandatory to realize the Hot and Energetic Universe science described in
the white paper is 99 Ms corresponding to 72% of 5 years observing time (assuming a observing
efficiency of 85% and 2% effective observing time for calibrations). For the Observatory science and
the discovery science 35 Ms (26%) of the time is allocated but it should be recognized that not all
observations listed under the Hot and Energetic Universe are required to realize the mission goals:
Table 2 Overview of the observing time (the percentages are rounded and do not sum to 100)
Category
Mandatory
Total (includes
Mandatory
[Ms]
multiple used
[% of total
observations)
time]
[Ms]
Survey (but about 10 Ms is accounted as part
26,6
36,0
20
Hot Universe
48,0
50,7
36
Energetic Universe (but some science drives
21,1
21,3
16
Observatory science1)
13,3
13,3
9
Discovery science
19,5
19,5
15
2,0
2,0
1
3,3
3,3
of the Hot Universe or Energetic Universe and
are also part of the survey)
the survey)
1)
Background1)
Calibration
Total observing time
observing time for specific targets relevant to
2
134,1
100
2,9
2
different science objectives
1)
Observatory science, discovery science and background observations are not mandatory for the core
science but are listed here to give a full overview of the expected observing plan. For the Observatory
science targets have been identified whereas for the discovery science this is not done.
A 5 year mission with an ambitious 85% observing efficiency and a 2 m2 effective area with 5 arcsec
resolution enables the science selected in the white paper. To realize this it is also required that by
selection of an optimal orbit and the optimization of the instruments, the fraction of not usable data
due to high background is small compared to XMM-Newton (70%).
-
the relative split between mandatory observations with the XIFU and the WFI is 58% to 42%. With a
typical regeneration time of the XIFU of less than 30% one may expect that this regeneration time of
the XIFU will not drive the mission lifetime or observing schedule.
-
The number of observations exceeding 100 ks is limited. In general these observations can be
interrupted for a shorter period for unloading the reaction wheels but much less than 50 ks
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uninterrupted time has the risk to create observing inefficiencies. The longer observations (also with
the X-IFU) can be split in multiple exposures without problems.
-
The total number of transient events for which a fast slewing is needed is about 100 (TBC) over the
5 year mission duration (typically 1 per every two weeks but the distribution will be random over
time).
-
The distribution of the known sources is shown in Figure 3-1 and Figure 3-2. Clearly the hot and
Energetic Universe science has a preference for targets outside the Galactic Plane. This is
representing the preference for these targets for a number of science topics (e.g. cluster redshift
study, deep sky observations). The not yet known sources (GRB, SN, TDE) will be distributed
uniformly over the sky except for the unknown clusters which are assumed to be at |b| > 10 o.
Figure 3-1
Distribution of sources (WFI and XIFU separate) over the sky. The WFI surveys can be seen as
set of connected red dots.
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Distribution of sources (required (A) and desirable (B) for the Hot and Energetic and required (C)
and desirable (C) for the observatory science (D)). Note that this division is not yet made!.
Clearly visible is the set of Galactic compact objects that are part of the observatory science.
-
In addition we can provide the total integrated exposure time over the sky for all the science given in
the corresponding mock observation plan. This is given in Figure 3-3.
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Figure 3-3 Total integrated exposure time over the mission duration to perform all science given in the white
papers
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App A. Mock Observation Plan: list of entries
In the mock observation plan we list the following information (in italic key information, other columns are
supporting columns for statistical purpose only):

Source name

Science group (0 = observatory, 1 = finding early groups, 2 = cluster velocity etc, see bottom of the
table)

Core science class (>1 required as it is class A, <0 important but not required (class B)

duplication (N if it occurs only once, Y if it appears in another program with a longer observation and the
same instrument, this is a manual check and a few cases may have been overlooked (or sources has two
different names such as Sersic159-03 and S1101)

Source classification (could also be survey)

RA (for most raster scans different positions are given with the exception of the 1 year survey for the
formation and growth of supermassive black holes (group 13)

Dec

l

b

number of observations

exposure time per observation [ks]

Total observing time (ks): (number of observations x exposure time per observation)

Total observing time corrected for duplications (the longest observation of a source/instrument
combination is used)

Class: Can be used to specify which targets are mandatory for a minimum mission success and which are
‘good to have’ but not critical for the mission success. A is mandatory to achieve core science
requirements, B good to have to accomplish the core science goals, C mandatory to achieve the
observatory science and D good to have to accomplish the observatory science. This column is currently
not used and not correctly applied but is left in the excel sheet for future use.

ToO (NO or, if yes identify the type with the following code: VF(<4 hrs), F(4-24 hrs), N(1-3 days),
S(3days-7 days), VS(1-3 weeks)

Continuous: Y if it is mandatory not to interrupt the measurement (this column is not consistently filled).
It should be noted that many of the > 50ks observations can be split into multiple observations. In
general it is, however, recommended not to separate them in time over more than a few weeks as the
science objective requires the full data to be completed.

Instrument: WFI or XIFU

Instrument mode: for WFI and X-IFU separately

Source intensity (either given by the ASST or by ESA (= Dave Lumb)) used to calculate the TM rates

Background critical: indication which observations depend critically on typical background variations
(factor 2 or 3). In general as rule bright point sources and faint sources or extended sources for which the
spectrum < 2 keV contains the scientific information are not critical dependent on the background. Note
that this is indicative only (in the MOP) and real cases can be different

TM rates: model, scaling to kBit/s, approximate TM rate and typical data volume (rate x observing time)

T_observation for X-IFU > limit_XIFU and T_observation for WFI > limit_WFI: observation time if the
source intensity is above the limit specified in the bottom of the table (now 10 and 1000 mCrab). The
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average intensity of the source is given in the 2 – 10 keV range which excludes variations in the source
intensity (can be significant for AGNs)

Source intensity: average source intensity from the RXTE mission in the 2 – 10 keV region

Source size: for clusters the R200 value and an assessment whether it is regular or irregular

Science goals: number science goal, note that some observations support more than a single science goal
and this can be seen in either more than a single value in this column or a source may appear twice with
the relevant switch (duplication) set to yes.

Science goal: reference to the numbers science goals in the mission proposal

Science topic (this one and the next are not checked on consistency)

Science subtopic

Synergy with other programs: identify other programs/topics that can use the specific target, thus
allowing to optimize the observing plan

Key measurement: identify the main observable/parameter of the observation

Justification and comment: on the required exposure time (plus any other comment you deem relevant
for that specific target

Observing strategy: summarize the observing strategy for each science topic/subtopic
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App B. Overview of changes in the MOP
In the table below we present the changes in the MOP since its first released version (1.1). Version 1.4 was
never completed but was used to assess the differences between the mission as proposed and the mission as
studied in the ESA CDF activity (December 2014). Following this the Athena Science Study team was
requested to study the differences in more detail (ASIE) and version 1.7 was used for this exercise. However,
the deadline of this exercise (May 2015) and the availability did not allow the have a full MOP consistent with
the updated science goals. This has been realized in version 2.0. Following the Mission Consolidation Review
and the recommendations by the Astronomy Working Group version 3.0 of the MOP was generated. By using
the observations for the cluster entropy (ER-SCIOBJ-121) also for the survey, the fraction of not allocated
time for core science was increased. Also the survey strategy was modified somewhat to take into account
the recommendation of the ASST at its 10 th meeting not to have an X-ray baffle as part of the baseline
design). Finally count rate estimates were added.
Table B.1
Overview of Mock Observation plan.
Science
objective
survey
Short description
MOP 2
28,54
14,9
5,6
4,0
24,50
MOP
ASIE
(1.7)
18,40
6,15
4,00
28,55
18,40
6,15
4,00
28,55
23,92
8,10
4,00
36,02
25 galaxy groups with gas temperature at z>2 to
investigate L-T relation
Kinetic energy dissipated from gravitational
assembly in 10 regular & 10 irregular galaxy
clusters
Cosmic history of the injection of entropy in cluster
hot gas at 0<z<2. Investigate 10 clusters in each
one of 4 redshift bins and 3 mass bins (total 120
clusters)
Metal production and dispersal in cluster hot gas
out to z=2. Observe 10 local clusters (needs
mosaicing) and 10 clusters per redshift bin per
mass bin out to z~2. Total 100 clusters.
Nearby clusters (z< 0.5)
Survey
Survey
survey
survey
survey
1,60
3,00
2,00
0,00
5,00
9,00
9,00
12,00
12,00
12,00
2,40
1,80
0,00
3,00
3,00
large area
modest area
deep observations
MOP
1.1
MOP
1.4
sum of survey
MOP 3
total
Hot Universe
R-SCIOBJ-111
R-SCIOBJ-112
R-SCIOBJ-121
R-SCIOBJ-122
R-SCIOBJ-131
R-SCIOBJ-132
R-SCIOBJ-133
R-SCIOBJ-134
R-SCIOBJ-141
Clusters z=0.5 – 2.0
9,00
9,00
9,00
9,00
9,00
Mosaic for nearby clusters (also 112)
0,00
0,00
5,00
5,00
See 112
total SCIOBJ 122
11,40
10,80
14,00
17,00
17,00
3,80
3,80
3,75
3,75
3,25
0,98
1,30
1,25
1,25
1,25
0,50
0,50
0,50
0,50
0,50
2,00
4,50
2,00
2,00
2,00
Bulk motions in 25 cluster cores with AGN, 10 of
them mapped in detail to explore microphysics in
detail
Detection of ripples in cluster gas created by AGN
jet activity, in a sample of 25 clusters
Heating-cooling balance in hot gas of 10 cluster
cooling cores
Shock speeds of expanding radio lobes in 10
clusters around radio galaxies per 2 redshift and 2
radio power bins
Detect 200 WHIM filaments in absorption, 150
towards BLLacs and 50 towards bright GRBs.
Determine metal abundances from emission lines
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in targeted regions
R-SCIOBJ-142
Cosmos field
Bridges and sculptor field
AGN
GRB follow up
1,20
1,80
5,30
5,00
2,00
1,00
5,00
5,00
2,00
1,80
5,26
2,50
2,00
1,80
5,26
2,60
sum SCI-OBJ 141
13,30
13,00
13,58
11,56
11,66
Detect WHIM filaments in emission associated to
absorption detected against 15 GRBs, after they
faded away
subtotal hot Universe
3,00
3,00
3,00
3,00
3,00
45,58
51,90
52,08
51,06
50,66
Detect 10 AGN 1043.0 < Lx<1043.5 erg/s at z=6-8
and 10 AGN 1044.0 < Lx<1044.5 erg/s at z=8-10.
Constrain SMBH seeds.
Detect at least 10 Compton-Thick AGN
1044<Lx<1044.5 erg/s per unit z at z~3. Map
obscured AGN/galaxy co-evolution.
Detect at least 10 warm absorbers in AGN
1044<Lx<1044.5 at z=1-4
Measure the mechanical energy of outflows in
luminous AGN at z=1-3, 10 per 3 luminosity bins
and per redshift bin.
Frequency and mechanical energy of UFOs at z=14
Wind energetics in 30 nearby AGN. Wind launch
physics from time-resolved spectroscopy of 10 AGN
Gas, metal and energy output from AGN and
Starbursts, using 25 (U)LIRGs with a variety of
AGN/Starburst ratios
Reverberation mapping of 8 bright local AGN
survey
survey
survey
survey
survey
survey
survey
survey
survey
survey
survey
survey
survey
survey
survey
3,00
3,20
3,20
Spin distribution (histogram) of 30 nearby SMBH
Measure spins of 8 Galactic BHs through various
methods. Winds and jets in 15 BHs. Gain insight
on BH birth though observations of 10 Supernovae
Accretion geometry around compact sources
through reverberation mapping. Study Tidal
Disruption Events and SgrA* (no TDEs version 3)
Probe ISM of z>7 galaxies by ToO observations of
25 GRB afterglows
10 TDEs (in 252 till version 3)
subtotal energetic Universe
Energetic
Universe
R-SCIOBJ-211
R-SCIOBJ-221
R-SCIOBJ-222
R-SCIOBJ-223
R-SCIOBJ-224
R-SCIOBJ-231
R-SCIOBJ-232
R-SCIOBJ-241
R-SCIOBJ-242
R-SCIOBJ-251
R-SCIOBJ-252
R-SCIOBJ-261
R-SCIOBJ-262
6,00
survey
survey
survey
survey
survey
3,10
4,50
4,50
4,50
4,50
0.75
2,50
2,20
1,69
1,69
2,38
3,00
1,70
3,80
1,70
3,72
0,00
3,33
2,50
3,70
2,96
3,72
5,00
3,72
2,40
2,05
3,10
3,30
1,60
1,65
2,50
2,50
2,50
2,50
1,25
20,50
23,73
23,86
26,01
1,20
21,31
0,64
0,64
0,64
0,64
0,64
0,95
1,00
0,95
0,95
0,95
4,28
4,38
4,40
4,15
1,80
1,04
1,02
1,04
1,04
1,04
0,17
0,18
0,17
0,17
0,17
-
-
-
-
0,61
Observatory
science
R-SCIOBJ-311
R-SCIOBJ-312
R-SCIOBJ-322
R-SCIOBJ-323
R-SCIOBJ-324
R-SCIOBJ-325
Atmospheres and exospheres of solar system
bodies (planets and moons) and cometary tails &
their interaction with Solar Wind.
Effects of stellar magnetic activity of 6 exo-planets
through repeated observations through their orbits
Wind interactions in binaries through phaseresolved spectroscopy in HMXB (30), LMXB (13)
and PNe (11). From version 3 only in 10 massive
binaries. (moved to 325 in version 3)
Magnetospheric accretion in 18 young low-mass
stars and brown dwarfs
Magnetic activity in 4 ultra-cool dwarf stars
Mass loss and winds in early type stars and in
HXMBs and selected OB associations
1,57
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R-SCIOBJ-333
Equation of state of dense matter from
observations of 10 neutron stars
Characterize fully the mass-loss and winds in 16
massive stars, both isolated and in binary systems.
Dropped and combined with 251
Determine M/R ratio of accreting white dwarfs
R-SCIOBJ-334
Geometry of magnetars and XDINs
-
-
-
-
0,50
R-SCIOBJ-335
PWN (was in 322)
-
-
-
-
0,80
R-SCIOBJ-336
3 nova and 10 planetary nebulae
-
-
-
-
R-SCIOBJ-337
Double degenerate binaries
R-SCIOBJ-341
Chemical composition of cold ISM through
absorption spectroscopy
Dust models and particle distribution through
scattering halos
Characterize warm and hot ISM in the Galaxy and
nearby galaxies
3D mapping of SNR from SN1a and SNcc
R-SCIOBJ-332
R-SCIOBJ-342
R-SCIOBJ-343
R-SCIOBJ-344
R-SCIOBJ-399
calibrations
background
Athena should be able to respond to scientific
challenges triggered by new developments,
including new multi-wavelength or other
messenger observations
5% of which half is when instrument is not in the
focus
total
in relevant documents (version 1.1, blank, ASIE
and MOP 2.0
GRB colow up (in MOP but class B already)
MOP corrected
MOP without duplications)
5 year mission (85%) [Ms]
observatory + discovery [%]
0,60
0,60
0,60
0,64
0,45
4,40
1,30
1,25
1,32
0
0,00
0,00
0,54
0,54
0,68
-
-
-
-
0,30
0,38
0,50
0,68
0,68
0,63
0,63
0,58
0,00
0,83
0,95
0,00
0,09
0,90
0,92
0,95
0,82
0,60
1,17
14,83
0,00
1,17
12,62
25,00
1,17
12,33
15,00
1,17
12,10
15,00
1,00
13,28
19,70
0,00
6,00
3,40
3,35
3,35
2,00
2,00
2,00
2,00
2,00
111,45
145,75
137,22
138,07
137,30
138,17
146,12
133,971)
134,03
0,10
138,07
135,19
134,03
20
20
Notes:
1)
After correcting for Wide Field Imaging observations which can also be used for the survey (e.g.
cluster entropy survey)
131,19
134,03
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App C. Source intensities of GRBs
The source intensities of GRBs have been estimated based on the source intensity distribution as observed by
Swift (private comm P. O’Brien) 4 hours after the burst onset. This information as been converted into the
corresponding 2 – 10 keV range using a spectral slope of -2. This gives one source at a 2 mCrab intensity.
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App D. Count rate estimates
In this section we report the estimated count rates based on private communication with the two instrument
teams. It is assumed that in a later stage this information will be formalized as part of the interface
documentation for the instruments.
Wide Field Imager
There has been an initial estimate for the countrates in the WFI and these are given as reference (WFI-MPEANA-0000-Data-Rate, IDI, 19/06/2015). The WFI countrates are based on simulations using the SIXTE
package and the main steps are listed below (numbers approximately correct):
-
estimates are made for 4 typical cases: Chandra Deep Field South, the Galactic Center, CasA and a
Crab-like source
-
For each event the multiplicity of the event is simulated (singles, doubles, etc). This varies typically
between 1.3 (CDFS) to 1.7 (other fields)
-
number of bits per pixel is 41 for the fast detector and 42 for the large detector
-
data compression of a factor 2.3 is assumed based on the simulations for the Crab data, for all other
no data compression is assumed.
-
A background component is assumed based on the instrument requirement of 5 10 -3 cnts/cm2/s/keV
-
a 5 sigma threshold on the pixel is assumed for frames corresponding to 5.1 kbit/s for the fast
detector and 12,7 kbit/s for the large detector
-
a housekeeping allocation of 4.3 kbit/s is included
-
a 20% margin is applied to the calculated data rates
-
Charge deposited by MIPs will be rejected onboard
Table 3
Overview of simulated countrates for the WFI (data rates include compression (Crab) and a 20%
margin and 1024 bits/kbit)
Field
CDFS
GC
Countrate
Data rate
Varia-
[events/s]
[kbit/sec]
bility
Typical sources and science objectives in MOP
40
40
1
Survey (R-SCIOBJ-111, 211, 222, 224)
208
53
1
Galactic center (R-SCIOBJ-351), planets (331)
2
Cluster entropy (R-SCIOBJ-121), cluster feedback (132,
134), reverberation (241), colliding winds in binaries (322),
magnetic accretion (323), mass loss in massive stars
CasA
10.861
913
Crab
121.494
4200
Not used for WFI
varying
Accretion geometry 15 GBH and 10 NS (251), Equation of
State (331), M/R of accreting white dwarfs (333)
background
37
1
WFI background measurement
0,3
1
Not used in MOP
large
background
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fast
X-ray Integral Field Unit
Reference, e-mail from Pajot (dd 18 May 2016) and the attached file ‘2016-05-17 data-budget.xlsx’. This
calculation includes the following components:
-
a source dependent component. An 1 mCrab source corresponds to 95 counts/s but it should be
recognized that AGNs af a given average source strength may vary up to a factor a few (5 is taken
as a reasonable safe number)
-
a source independent component which is considered stable but it should be recognized that
especially for the background component this is not correct (but this is taken into account in the
applied margin). These components are given in Table 4.
Table 4
countrate estimates for the X-IFU
Component
Value
Event
Margin
kbit/s
(per
size1)
[%]
(without
second)
comment
header)
Source
mCrab
64
20
7,3
Scales with source intensity
Cryoac rate
40 counts
40
100
3,2
Based on cryoAC analysis, data are
transferred to the ground for correlation
with the TES
particles in TES
22 counts
64
200
4,3
Area of TES is about half of the cryoAC. It is
assumed that the particles deposit an
energy in the 0.2 – 15 keV range in the TES
(is a conservative approach) and cannot be
identified onboard
Total sky
1 counts
background
integrated
64
100
0,1
Foreground and Cosmic X-ray background
(0,3 counts/s)
over array
Calibration
2400
40
0
96
events
Assumes no data processing onboard
except selection of events in lines and a
reduced energy grid only accurate around
lines.
House keeping
10 kbit/s
20
12
Estimate (300 parameters @ I1 Hz, 3000
parameters @ 1/8 Hz
Total stable
1)
116
Dominated by number of calibration events
Event size includes typically a 20% margin
In practice this gives a number of cases for the Mock observing plan taking into account that the instrument
has a requirement of 30% throughput for a 1 Crab source. Whether or not this TM rate for the very intense
sources is achieved by buffering onboard over more than one telemetry pass or not is not part of the MOP. It
Athena
ASST
Doc. no. : SRON-ATH-PL-2014-001
MOCK
OBSERVATION
PLAN
Issue
: 3.0
Date
: 15 September 2015
Cat
:
Page
: 26 of 26
should also be noted that in case of long observations of bright sources (e.g. SAX J1747.0-2583) the
observation can be split into several separate observations spread over time.
Source strength
TM rate [kbit/s]
comment
including overhead
(headers etc)1)
1 mCrab
145
Requirement for high-res events
10 mCrab
220
Goal for high res events
50 mCrab
550
100 mCrab
980
300 mCrab (which is the
maximum required rate
2650
Requirement for throughput with 30 eV
resolution: less bits can be applied per event
(requirement is still TBC)
1) The overhead for packing is assumed to be 15%, in the MOP we apply for variable sources typically a factor 5
margin for the source strength