Download Transient Science Server (QUB)

Transient Science Server (QUB)
PS1 team at QUB : thanks to Dave Young, Ken Smith, Maria Teresa Botticella
• Transient science is key goal for PS1
• Estimated real transient event triggers : ~ 2 x 105 per
night
• How do we classify these in a probabilistic way
• High-z, SCP, SNLS, Essence : successful type Ia
identification
Massive star SNe
•
•
•
•
•
•
Ultra-bright IIn SNe
Pair-instability SNe
Black-hole forming, quenched
explosions
GRB SNe Ic + jet driven
explosions
Electron-capture SNe
Low-Z, low-z, large volume
PS1 goal : explosions
of the most
massive stars
Young, Smartt et al. 09
•
•
•
•
ROTSE : 0.4m, 4 sq degrees
Found the most luminous SNe
known
Large local volume, good image
subtraction, high cadence
Quimby et al. 2007
Static Transients
Search Template Difference
Supernovae
Variable stars
AGN
*
* ~500,000
~500,000 static
static transients
transients -- not
not
all
all supernova
supernova
*AGN,
*AGN, SN,
SN, variables,
variables, etc
etc
*This
*This is
is were
were our
our work
work begins
begins -wealth
wealth of
of tranisents
tranisents
Artifacts
Images from SDSS II SN Survey.
Sako et al. (2008)
Initial attempt : Astrogrid enabled
Flag interesting
interesting objects
objects
Flag
MOPS SQL
SQL Database
Database
MOPS
Select out
out static
static transients
transients and
and apply
apply
Select
25σ detection
detection selection
selection filter
filter
aa 25σ
Calculate additional
additional
Calculate
parameters for
for SN
SN
parameters
candidates
candidates
e.g. distance,
distance,
e.g.
absolute magnitude,
magnitude,
absolute
transient // match
match
transient
separation.
separation.
Use the
the VO
VO to
to cross-match
cross-match transients
transients
Use
against various
various catalogues
catalogues
against
2MASS PSC
PSC
2MASS
USNO-B1
USNO-B1
2MASS XSC
XSC
2MASS
NED
NED
SDSS .....
.....
SDSS
Merge and
and filter
filter the
the results
results
Merge
SN (rated) Variable stars Others
Generate VOEvent
VOEvent
Generate
for objects
objects of
of
for
interest
interest
Publisher
Publisher
Ingest results
results into
into
Ingest
MySQL database
database
MySQL
AGN (rated)
Webpage for
for each
each
Webpage
individual SN
SN or
or
individual
AGN candidate
candidate
AGN
Publish webpages
webpages
Publish
Catalogue
Locally Ingested Catalogues
DB Table Size
DB Index Size
Guide Star v2.3
144GB
79GB
2MASS Point Sources
128GB
SDSS Photo Stars
24GB
SDSS Photo Galaxies
NASA Extragalactic Database
# Rows
# Columns
Data Source
945,569,477
58
NAOC China
470,992,970
66
VizieR
16GB
180,375,324
26
SDSS DR7
32GB
14GB
174,923,308
39
SDSS DR7
2.7GB
393MB
6,090,527
135
Caltech
2MASS Extended Sources
358MB
134MB
1,647,599
30
VizieR
SDSS Spectroscopi
c Galaxies
114MB
74MB
807,740
28
SDSS DR7
Veron AGN v12
17MB
8.6MB
108,080
30
VizieR
Total Catalogue Storage (so far)
52GB
0.5 TB
Hardware
DELL PowerEdge 2950 III
4 Core Xeon X5460 (3.16 GHz)
1 TB (RAID 5) Internal SAS
Storage
Transient Server Database Logs
& Temporary Tables
DELL PowerVault MD3000
5.3 TB (RAID 5) SAS Storage
Array
Transient Server Database Tables
DELL PowerVault MD1000
11.2 TB (RAID 5) SATA Storage
Array
Transient Server FITS Images
Follow-up Data
Database Backup Staging
Cross-matching and filtering using the VO
Catalogue of
of ~5x10
~5x1066 static
static transient
transient sources
sources from
from IPP
IPP
Catalogue
YES
AGN
AGN
Is transient
transient within
within 0.5”
0.5” of
of 2MASS
2MASS PSC?
PSC?
Is
NO
YES
Variable Star
Star
Variable
Is transient
transient within
within 0.5”
0.5” of
of 2MASS
2MASS XSC?
XSC?
Is
NO
YES
AGN
AGN
Is transient
transient within
within 0.5”
0.5” of
of USNO-B1
USNO-B1 source?
source?
Is
NO
YES
Variable Star
Star
Variable
Is transient
transient within
within 2”
2” of
of source
source in
in Veron
Veron et
et al.
al. catalogue?
catalogue?
Is
NO
Variable Star
Star
Variable
YES
Is transient
transient within
within unique
unique search
search radius
radius of
of source
source in
in nearby
nearby galaxy
galaxy catalogue?
catalogue?
Is
NO
YES
SN
SN
SN
YES
Is transient
transient within
within 2’’
2’’ of
of NED
NED source?
source?
SN
Is
NO
Is NED
NED source
source classified
classified as
as AGN?
AGN?
Is
Does NED
NED source
source have
have aa redshift
redshift measurement?
measurement?
NO
Does
YES
Is transient
transient within
within 1’
1’ of
of NED
NED source?
source?
Is
NO
YES
Is transient
transient within
within 0.5’’
0.5’’ of
of SDSS
SDSS star?
star?
Is
NO
NO
Is transient
transient within
within 10’’
10’’ of
of SDSS
SDSS galaxy?
galaxy?
Is
YES
NO
SN
SN
Other
Other
NO
YES
Is transient
transient within
within 35Kpc
35Kpc
Is
of NED
NED source?
source?
of
AGN
AGN
SN
SN
YES
SN
SN
AGN
AGN
Transient Processing Algorithm
Tidal disruption events
Gezari,
Heckman,
Lawrence et al.
Transient Classification Processing Speeds
Number of threads
•
•
•
•
Units
1
20 per sec
4 ( = number of CPUs)
60 per sec
Total capacity
•
Value
5,000,000 Transients per day
Tested the use of remote catalogues and VO query tools with a
similar decision tree classifier
Processing speed ~50,000 transients in ~4 hours
Complaints from NED administrators !
In-house database : ~800,000 in ~4hrs
PS1 Transients will be public
PS1 + PS2 ~ 2012
Pan-STARRS 4 – Mauna Kea 2015 (+PS1 & PS2 = PS6 ?)
LASST = PS16 – 4x PS4 around the world
- science on the way
- under consideration by US Decadal Review
Summary
• Main challenges for PS1 now in
computation and software
• Similar issues to other wide-field surveys
(WFC Surveys, SDSS, UKIDSS, VISTA)
• Long term archiving open question
• Transient Science is new (but CSS,
ROTSE, NSF excellent examples)
• PS“n” is on the table for the UK
• Economic benefits – underplayed ?