The Catalina Real-time Transient Survey: The Catalina Real-time Transient Survey: An Open Optical...
-
date post
21-Dec-2015 -
Category
Documents
-
view
222 -
download
3
Transcript of The Catalina Real-time Transient Survey: The Catalina Real-time Transient Survey: An Open Optical...
The Catalina Real-time The Catalina Real-time Transient Survey:Transient Survey:An Open Optical Transient Survey
Sept 19th, 2011Sept 19th, 2011
Andrew Drake, George Djorgovski, Ashish Mahabal,
Roy Williams, Matthew Graham, Ciro Donalek (Caltech),
Jose Prieto (Carnegie Obs), Marcio Catelan (PUC Chile),
Edward Beshore, Steve Larson (LPL)
Andrew Drake, George Djorgovski, Ashish Mahabal,
Roy Williams, Matthew Graham, Ciro Donalek (Caltech),
Jose Prieto (Carnegie Obs), Marcio Catelan (PUC Chile),
Edward Beshore, Steve Larson (LPL)
[email protected]://crts.calech.edu
The Catalina SurveysThe Catalina Surveys
•Catalina Real-time Transient Survey (CRTS) is a Caltech operated transient survey that started in Nov 2007 using from the Catalina Sky Survey (CSS).
•CSS is an NEO survey that began operation in March 2004.
• CSS operates three telescopes. Two in Tucson AZ & one in Siding Spring, Aus.
ObservationsObservations
• All CSS observations are taken unfiltered.• Observations 21 days/lunation.• Cover up 2000 sq. deg/night.
• With 4 images.• Mags ~19 – 21.
• Each telescope has an identical camera:
–Spectral Instruments camera with Imager Labs thinned 4K2 CCD.–14 second downloads
Catalina Sky Survey DiscoveriesCatalina Sky Survey Discoveries
Catalina Sky CoverageCatalina Sky Coverage
Total Catalina coverage 33,000 sq deg.
RA=0h
RA=12h
Catalina Transient SurveyCatalina Transient Survey The CRTS survey searches for highly varying astronomical The CRTS survey searches for highly varying astronomical
sources (sources (““optical transientsoptical transients””).).
Transients are found based on catalog comparisonsTransients are found based on catalog comparisons CSS coadds, USNO-B, PQ, SDSS.CSS coadds, USNO-B, PQ, SDSS. Remove artifacts and asteroids by detection coincidence and motion.Remove artifacts and asteroids by detection coincidence and motion.
All data is fully processed within minutes of observation.All data is fully processed within minutes of observation.
All discoveries are made public instantly to enable rapid follow-up.All discoveries are made public instantly to enable rapid follow-up.
Discover ~ 1 OT /10^6 measurements.Discover ~ 1 OT /10^6 measurements.
TransientsTransients
CRTS has discovered ~4000 transients.CRTS has discovered ~4000 transients. CSS 0.7m telescope, 4ys ~2100 OTs MLS 1.5m telescope, 2yrs ~1600 OTs SSS 0.5m telescope, 1yr ~300 OTs
CRTS transient discoveries include…CRTS transient discoveries include…
Main Transient TypesMain Transient TypesSupernovae ( > 800 discovered)2009+2010 twice number published by any other group(PTF, PanSTARRS, LOSS, etc.).
Cataclysmic Variables (> 500 discovered)More than any pastsurvey (eg. SDSS).
UV Ceti stars (flare stars)~100 discovered
Blazars>100 discoveredso far
100’s more transient sources100’s more transient sources
AGN-disk SN (CSS100217).AGN-disk SN (CSS100217).
Pair Instability SNe (SN 2009jh & SN 2007bi).Pair Instability SNe (SN 2009jh & SN 2007bi).
Young Stellar Objects (FU Ori, T Tauri)Young Stellar Objects (FU Ori, T Tauri)
High Proper Motion starsHigh Proper Motion stars
Classical Novae (CSS081007)Classical Novae (CSS081007)
Tidal disruption events (archival)Tidal disruption events (archival)
Extragalactic Luminous Blue VariablesExtragalactic Luminous Blue Variables
Variable stars (LPV, RR Lyrae)Variable stars (LPV, RR Lyrae)
Discovery LocationsDiscovery Locations
Red=SN, Blue = CV, Green=Blazar, Magenta=Other Galactic Coords.
SN red, CVs blue, blazars green, all others magenta.
Dwarf Nova type CVsDwarf Nova type CVsDwarf Nova type CVsDwarf Nova type CVsDelta mags up to 8.Rise time ~1-2 days.Repeat time days to decades.Possible transient fog for LSST.
Flare StarsFlare StarsFlare StarsFlare Stars
Flare of LHS-2397aFlare of LHS-2397aFlare of LHS-2397aFlare of LHS-2397a
1 2
3 4
Discovery NotificationDiscovery Notification
Three layers of event distribution.Three layers of event distribution.1) Real-time discovery (mins)
VOEvents, SkyAlert, iPhone
Automated Event DistributionAutomated Event Distribution
http://skyalert.org
Discovery data -> VOEvent xml. Notices published to SkyAlert.org, etc. Automated discovery agents create a portfolio from VO services (SIMBAD, NED, etc.) & catalogs (SDSS, NVSS, etc.)
Discovery NotificationDiscovery Notification
Three layers of event distribution.Three layers of event distribution.1) Real-time discovery (mins)1) Real-time discovery (mins)
VOEvents, VOEvents, SkyAlert
2) Human classified (mins-hrs)Event portfoliosHTML, iPhone, Circulars, Twitter
Classified EventsClassified Events
http://crts.caltech.edu
Evaluation of past information Including: light curves, images, colours, nearby sources (eg. x-ray, radio, galaxies) -> classification.Info on classification also published as VOEvents to SkyAlert.org.
Discovery NotificationDiscovery Notification
Three layers of event distribution.Three layers of event distribution.1) Real-time discovery (mins)1) Real-time discovery (mins)
VOEventsVOEvents
2) Human classified (mins-hrs)2) Human classified (mins-hrs)Event portfoliosEvent portfoliosHTML, iPhone, Circulars, TwitterHTML, iPhone, Circulars, Twitter
3) Events of interest (mins-days)Portfolios + follow-upATel, CBAT, VSNET
Extreme SupernovaeExtreme Supernovae
Extremely long timescale SNeExtremely long timescale SNe
Extremely bright SNeExtremely bright SNe
SN associated with very faint galaxiesSN associated with very faint galaxies
Long Lasting Supernova 2008iyLong Lasting Supernova 2008iy
Longest brightening Longest brightening supernova.supernova. Took ~400 days to brighten. Took ~400 days to brighten. ~20 times longer than a ~20 times longer than a
normal type Ia supernova.normal type Ia supernova. Type IIn SN.Type IIn SN.
Found in a galaxy ~500 Found in a galaxy ~500 times fainter than the Milky times fainter than the Milky Way.Way.
Catelan et al. 2009, CBET#1780
Host galaxy star
Long Lasting Supernova 2008iyLong Lasting Supernova 2008iy
Spectra of 2008iySpectra of 2008iy Black, Red P200 Cyan BTA 6m Green SMARTS
Long Lasting Supernova 2008iyLong Lasting Supernova 2008iy
Light curves of SN 2008iyLight curves of SN 2008iy
Shock breakout in SN2008iyShock breakout in SN2008iy
Normalized flux curves of 2008iy comp. to stretched Normalized flux curves of 2008iy comp. to stretched SN 2006gy and other SN.SN 2006gy and other SN.
O
O
4yrs later still going strong.4yrs later still going strong.
Keck spectrum of SN2008iy Keck spectrum of SN2008iy 1450 days after explosion! 1450 days after explosion!
Drake et al. 2011 in prep.
CSS100217CSS100217Luminous SN IIn, TDE, or AGN variability?Luminous SN IIn, TDE, or AGN variability?
• CSS light curve.CSS light curve.
CSS100217CSS100217
. SDSS NLS1 host galaxy spectrum. SDSS NLS1 host galaxy spectrum
CSS100217CSS100217• BPT emission diagramBPT emission diagram • NLS1 variabilityNLS1 variability
1500 SDSS NLS1 (Zhou et al. 2006)
CSS100217CSS100217
Follow-up spectraFollow-up spectra
CSS100217CSS100217• Event light curveEvent light curve
• Peak temp ~10^4K, Peak temp ~10^4K, weak radio, rapid varweak radio, rapid var
=> not TDE or AGN• SN IIn spectra SN IIn spectra (narrow +
evolving broad Balmer features) and SN light curve.and SN light curve.
Peak mag = -23 withPeak mag = -23 with
Ltot =1.3x10^52 ergLtot =1.3x10^52 erg
=> Most energetic and luminous SN known
Drake et al. ApJ 2011.
SN Host GalaxiesSN Host Galaxies
CRTS
Lick Obs Supernova Search (LOSS)
SN host galaxy mags.SN host galaxy mags.
Faint-galaxy Supernova SN 2008hpFaint-galaxy Supernova SN 2008hp Type Ia supernova Type Ia supernova Found in very faint Found in very faint
nearby galaxy.nearby galaxy. Redshift z=0.027Redshift z=0.027 Host Mr=-12.4,Host Mr=-12.4, ~7 mags ~7 mags
(~600x) fainter than the (~600x) fainter than the supernova itself.supernova itself.
Very few stars, so expect Very few stars, so expect few SNe.few SNe.
Host galaxy
SDSS image
Releasing the CSS datasetReleasing the CSS dataset
Six years of data from each telescope.Six years of data from each telescope. 1.5 million 4x4k images.1.5 million 4x4k images. History of 500 million discrete objects.History of 500 million discrete objects.cf. USNO-B 1 billion, SDSS dr7 ~400 million.
80 billion photometry points.80 billion photometry points.cf. USNO-B 3.6 billion, SDSS dr7 2 billion, COROT 290 million.
All CSS data is online &All CSS data is online & CRTS is making it all public.CRTS is making it all public.
Catalina Data ReleaseCatalina Data Release
During this workshop 1000 sq. deg.120 < RA < 240, 11 < Dec < 20:http://nesssi.cacr.caltech.edu/cgi-bin/getcssconedbvao.cgi
All CSS photometry will be released by November.
Transients SummaryTransients Summary~4000 unique optical transients:~4000 unique optical transients:>800 SNe.>800 SNe.>500 CVs.>500 CVs.>100 Blazars.>100 Blazars.>100 Flare stars.>100 Flare stars.~500 High amp vars, AGN, HPM stars, ~500 High amp vars, AGN, HPM stars,
etc.etc.
CRTS SummaryCRTS Summary CRTS has discovered ~4000 optical transients.CRTS has discovered ~4000 optical transients. All CRTS discoveries are made public All CRTS discoveries are made public
immediately (cf. PTF, PanSTARRS).immediately (cf. PTF, PanSTARRS). Discoveries include many extreme examples of Discoveries include many extreme examples of
supernovae.supernovae. During this workshop 1000 sq deg of photometry During this workshop 1000 sq deg of photometry
(120 < RA < 240, 11 < Dec < 20) is available at: (120 < RA < 240, 11 < Dec < 20) is available at: http://nesssi.cacr.caltech.edu/cgi-bin/getcssconedbvao.cgi
CRTS will make all CSS photometry public by CRTS will make all CSS photometry public by November.November.
http://crts.caltech.edu/CRTS is supported by NSF Grant No. AST-0909182
Fin.Fin.
Publications Publications
CRTS Circulars (> 1500)CRTS Circulars (> 1500) twitter.com/skyalert
Astronomer’s Telegrams (> Astronomer’s Telegrams (> 50)50)www.astronomerstelegram.org
CBETS (> 100) CBETS (> 100) www.cfa.harvard.edu/iau/cbet/RecentCBETs.html
VSNET Alerts (> 100)VSNET Alerts (> 100)www.kusastro.kyoto-u.ac.jp/vsnet/
• Journals (>25, mostly collaborative)Journals (>25, mostly collaborative)crts.caltech.edu/pub.html
Shock breakout in SN2008iyShock breakout in SN2008iy
Before During Breakout Difference
FU Ori Star CSS091110FU Ori Star CSS091110FU Ori Star CSS091110FU Ori Star CSS091110CSS lightcurve
HPM StarsHPM StarsHPM StarsHPM Stars
2005-06-03 2007-03-14
2008-03-10 2009-04-18
2MASS J14442067-2019222
CSS lightcurve
SummarySummary
CRTS has so far discovered …CRTS has so far discovered …
Automated Detection FilteringAutomated Detection Filtering
Detection coincidence filtering.Detection coincidence filtering. Image artifact filtering.Image artifact filtering. CSS coadd source comparison.CSS coadd source comparison. Remove known MPC asteroids.Remove known MPC asteroids. Motion filtering of new asteroids.Motion filtering of new asteroids. Discovery rate is ~ 1 OT /10^6 measurements.Discovery rate is ~ 1 OT /10^6 measurements.
Event follow-up Event follow-up
Supervised follow-up strategy: Supervised follow-up strategy: Photometry firstPhotometry first
P60, NMSU, DAO, HTN, CSS 1m (2011) (2011)
Spectroscopy only for transients appearing unusualSpectroscopy only for transients appearing unusual(avoid common SN like Ia(avoid common SN like Ia’’s based on colour normal luminosities) .s based on colour normal luminosities) .
Gemini N+S, Keck, P200, SMARTS, IGO, MDM.
External follow-up:External follow-up:
Foster follow-up of other transients by open publication Foster follow-up of other transients by open publication and collaboration.and collaboration.
ClassificationClassification
Review historical info.Review historical info. Broad light curve classes (CVs, SN, Vars, AGN).Broad light curve classes (CVs, SN, Vars, AGN). Comparison DSS, SDSS, PQ cats/images.Comparison DSS, SDSS, PQ cats/images. Datascope for: NED, SIMBAD, Downes, GCVS, Datascope for: NED, SIMBAD, Downes, GCVS,
FIRST, NVSS, 2MASS, ROSAT, Vernon, FIRST, NVSS, 2MASS, ROSAT, Vernon, CGRABS, etc.CGRABS, etc.
Combine elements to gain overall picture.Combine elements to gain overall picture.
Catalina Sky CoverageCatalina Sky Coverage
CSS Schmidt coverage ~23,000 sq deg
Long Lasting Supernova 2008iyLong Lasting Supernova 2008iy
Light curves of SN 2008iyLight curves of SN 2008iy LC of 2008iy comp. shifted & LC of 2008iy comp. shifted & stretched SN 2006gy.stretched SN 2006gy.