Download Five Years of Swift Science: GRBs and More!

Five Years of
Science:
GRBs and More!
John Nousek (Penn State University)
Neil Gehrels (Goddard Space Flight Center)
International Workshop on Astronomical X-ray Optics - Prague, Czech Rep. – 6-9 Dec. 2009
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Swift launch:
20 Nov 2004 !!
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5th Anniversary of Swift Conference
•
Celebration of Swift held at Penn State, 18-20 Nov. 2009
•
Attracted more than 150 participants – 1/3 Penn State, 1/3 US & 1/3
from ten other countries
•
Discussed impact of Swift on areas of astrophysics, and planned for
future developments and science direction of the Swift Observatory
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Swift GRB Science
Swift has redefined the field of GRB science.
 GRB backgroud
 Swift comparisons
Duration
Host galaxies
Distance distributions
Energetics
Beaming
ARAA Annual Reviews 2009 Gehrels, Ramirez-Ruiz and Fox
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GRB Properties
Two types:
Short GRBs (t < 2s)
Long GRBs (t > 2s)
ARAA
article
GRB 990123
HST image
Fruchter et al.
Redshift range:
0.2 - ~2 SGRBs
0.009 - 8.2 LGRBs
Energy release in -rays:
1049-1050 ergs SGRBs
1050-1051 ergs LGRBs
Jet opening angle:
~15 deg SGRBs
~5 deg LGRBs
Both types have delayed
& extended high-E emission
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GRB Spectra
afterglow with
synchrotron fit
prompt
GRB 051111
Butler et al. 2006
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VELA
GRB discovery
1973
Compton / BATSE
isotropy &
inhomogeneity
2 duration classes
1991
Compton / EGRET
GeV extended emission
1994
short long
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BeppoSAX
afterglow & distance
1997
Fireball Model
1997
Mészáros & Rees 1997
HETE-II
GRB030329 / SN2003dh
XRFs
~ 2003
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UVOT
XRT
Swift Mission
3 instruments, each with:
- lightcurves
- images
- spectra
Rapid slewing spacecraft
Rapid telemetry to ground
BAT
UVOT Position - < 1 arcsec
BAT Position - 2 arcmin
XRT Position - 5 arcsec
BAT
XRT
T<10 sec
.
T<90 sec
T<2 min
475 GRB as of 1 Nov 2009
85% with X-ray detections
~60% with optical detection
155 with redshift (41 prior to Swift)
46 short GRBs localized (0 prior to Swift)
Swift Statistics
Short GRB
Fast Rise Exponential Decay
Short GRB
Swift GRB Data
XRT lightcurve
GRB 091029
BAT lightcurve
UVOT image
GRB
Swift GRB Data
XRT lightcurve
GRB 091029
flare
BAT lightcurve
steep-flat-medium shape
UVOT image
GRB
long
Hard
Soft
Hardness Ratio
short
Duration (s)
Time (s)
Short
vs
Long
Time (s)
•
short
long
Kouveliotou et al. 2003
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GRB Spectroscopy
z
Time
GRB
(109 years)
8.3
6.7
6.29
5.6
5.3
5.11
GRB 080607
13.0
12.8
12.8
12.6
12.6
12.5
090423
080813
050904
060927
050814
060522
Optical Brightness
K = 20
K = 19
J = 18
I = 16
K = 18
R = 21
@ 20 min
@ 10 min
@ 3 hrs
@ 2 min
@ 23 hrs
@ 1.5 hrs
Prochaska et al.
2008
Savaglio
2006
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Blast from the past!
GRB 090423
z = 8.29
•
look back time = 13.0 billion light years
Lyman break redshifted from UV to IR
GROND Greiner et al
Tanvir et al. 2009; Salvaterra et al. 2009
McMahon & Tanvir
Evolution of Swift Operations – GRBs & More!
• Original prime mission: 2004-2006 – Swift the GRB Explorer
• Up to Nov. 2004 – Pre-launch:
– Swift primarily a GRB detection and afterglow followup mission
– Ground-breaking operations design allows immediate response to GRBs
– Automated follow-up allows introduction of new GRB without new
schedule
– Targets of Opportunity limited to new non-Swift GRBs or rare events
• Expected schedule re-plans only once / month; ToO once / week
– Planning using TAKO software / five times a week
• Prime mission – 2005-2006:
– Execution closely follows plans, except:
• XRT TEC power supply fails, forcing operations to passively maintain XRT
below -50 C
• Automated target process is great success allowing highly flexible and rapid
ToO response
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Swift Operations Currently
• 1st mission extension: 2006-2008 – High-z GRBs and the GI Program
– Swift reduces time on late afterglow followup and increases effort on
finding high redshift GRBs
• Swift introduces GI targets, followed by pressure for increased ToO and
monitoring campaigns
– TAKO planning software modified to incorporate XRT temperature
control; other ancillary software improves ACS reliability
– Improved ToO automation allows multiple ToOs in short period without
new schedule (including nights and week-ends)
– Targets of Opportunity and
Monitoring Campaigns occur
every day
• Typical load of 4-12 ToO or
Monitoring observations
every day
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Supernova Studies with Swift
XRT and UVOT observations of SNe
- 66 observed to date of all types (26 Ia, 18 Ibc, 22 II)
- UV, optical & X-ray densely-sampled light curves
- Largest sample of SN light curves in the UV
- Unique UV characterizations of SN Ia's (incl UV spectra)
XRT
UVOT opt
UVOT UV
SN 2006bp
(Type IIP)
Supernova
Lightcurves
Immler et al. 2007
Brown et al. 2008
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X-Ray SN Studies
- XRT observations probe SNe
environments & mass-loss rates
SN 2008bo
- Signature of SN shock traveling
through dense shell
- Shells are outer H/He-rich layers
from Luminous Blue Variable phase
SN 2006jc
SN 2006bp
Immler et al.
SN 2008D Shock Breakout
SN 2007uy
- XRT monitoring of NGC 2770 (27 Mpc)
revealed extremely luminous X-ray outburst
- EX ~ 2x1046 ergs
- No BAT, no radio late >> probably no jets
- UVOT detection of SN rising 90 min later
- SN Ib/c
- Shock breakout. May occur for all SN
9 Jan 2008
Soderberg et al. 2008
Nova Studies with Swift
Thermonuclear detonation of accumulated accretion
on white dwarf
- 25 novae observed
- Rise and fall of few keV emission from
shocked ejecta
- Super-Soft emission in some from
WD surface (kTBB ~ 30 eV)
1.6 kpc
RS Oph
- Extensive observations of RS Oph 2006
(~400 ksec) revealed unexpected
luminous SSS state and 35 sec QPO
- Earth mass ejected at ~4000 km/s into wind
of companion Red Giant
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Swift Trigger on Large Stellar Flare
•
BAT triggered on a stellar flare from nearby
(d=5 pc) EV Lac (dM3e, Prot ~4 days)
•
XRT spectra show Fe K 6.4 keV emission
first for an active dMe star
EV Lac
25 Apr 2008
•
UVOT enhancement large but unknown:
instrument safed at >200,000 counts/s
•
Brightest stellar flare observed
•
Erad ~ 1038 erg
•
EV Lac is young magnetically active
isolated star.
–
Previous super-flare was from binary
RS CVn system, II Peg
Osten et al 2007, 2008
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BAT Sky Monitoring
SWIFT J1816.7-1613
4U 0115+634
Newly discovered source (Atel #1456)
Known pulsar in outburst (Atel #1426)
536 sources monitored
65 detectable on a daily basis
Krimm et al
~60 with > 30 mcrab outbursts
~15 mCrab sensitivity in 1 day
http://swift.gsfc.nasa.gov/docs/swift/results/transients/
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TOOs for Transients & GRBs
- Swift can perform rapid X-ray and optical observations of transients
- TOO rapidly uploaded as RA & DEC. Response time is <1 hour to 1 day
- Web page for TOO requests
http://www.swift.psu.edu/too.html
- Duty scientists always on call for urgent TOOs
- New "command from home" mode for after-hour TOOs
- Expert international teams provide rapid advice
* GRB follow-up
(48 members)
* Supernova
(22 members)
* CVs & novae
(24 members)
* Hard X-ray survey
(18 members)
* AGN
(4 members)
* GeV and TeV -rays
(4 members)
- Daily planning telecon to decide schedules
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Swift Operations Ahead
• 2nd mission extension: 2009-2011 – Swift: the ToO Observatory
– Swift executes ~70-75 separate pointings per day
• Each pointing is planned, although significant labor by human science
planner to have each pointing a different target
– Under an initiative approved by 2008 Senior Review, MOC has
conducted an Automation Initiative to streamline science planning
– Elements include:
• Target management database – MySQL database to automatically
ingest target information from ToO requests, target lists from GI
approved proposals and GRB information from GCN circulars
• More highly automated TAKO software – will allow higher
automation to XRT temperature control and ACS slew behavior
– Goal is to allow faster, easier science planning, with capability to
increase GI monitoring campaigns and rapid ToO response to large
numbers of targets
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Conclusions
• Swift has delivered a remarkably successful science mission to date,
powered by an innovative operations concept that has continued to
evolve as driven by scientific interest
• The latest changes will enable an even more responsive
observatory, giving more GI monitoring and ToO responsiveness
• For Senior Review 2010, How do you suggest ways to use Swift, and
how is that important for astrophysics?
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Cosmic Timeline & Early Universe Probes
z=12
z=5
z=0
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Hint That These Probes Work
z=6.29
z=6.28
GRB 050904
SDSS Quasar
We Need Higher Redshift Observations
• Swift & SDSS only probed the very near edge of reionization
• We need a statistically significant sample that probes well into
the epoch of reionization
– We need to find 30-50 GRBs from 5<z<12
• ~10x what Swift found (5<z<7)
– We need to find 200-400 quasars from 6<z<10
• ~10x all z>6 quasars found (6<z<6.5)
z=12
z=5
Current Capabilities & Needs
• Current capabilities from Swift & SDSS needed to observe high redshift
objects are:
– Rapid localization and observations of GRBs
– Rapid notifications to enable observations by other facilities
– A very large field of view for finding GRBs & quasars
• BREADTH versus Depth for rare objects (Critical)
• To probe high redshift objects we need:
– Greater sensitivity to high redshift bursts
• Redshifted gamma-ray photons into the X-ray
– Prompt, uniform follow-up of afterglows in the IR (Critical)
– Rapid redshift determination (in minutes)
– Observations above the atmosphere are essential to eliminate
terrestrial lines that confuse surveys
The Solution: JANUS
1960
1980
ABC
BCD D
EF
Testing
GHI
JKL
XYZ
Support
2000
RST
TUV
1970
1980
1990
2000
2010
2020
Increasing Capabilities
Space Network
X-Ray Flash Monitor
(XRFM): Detects &
localizes high-z GRBs
VWX
1960
1-20 keV, 4 sr field-of-view
Near-IR Telescope
(NIRT):
High-z GRB & quasar
spectroscopy
0.7-1.7 μm, 1″ pos,
redshifts,
0.36 degree2 field-of-view,
Spacecraft:
Rapid communication
w/ ground, rapid
slewing (50°/100 sec),
stable platform
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JANUS Mission Concept – Sky Survey Mode
~400 quasars
20,000 square degree
Survey
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JANUS Mission Concept – GRB Mode
~50 GRBs
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JANUS Objectives
•
•
•
Determine star formation history
• by using ~50 GRBs
Explore the coevolution of
galaxies & black holes
• by using ~400 quasars
Determine if dominant source of
reionization
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