Surveys for fast transients present and future
Gavin Ramsay
(Armagh Observatory)
Wednesday 20 January 2010
Definition of fast transients:
- Sources which significantly change their brightness
on timescales of a few hours or less;
compact sources,
eg, GRBs, Novae, Accreting Binaries, Single Stars etc.
Why they are interesting sources to study?
- Can study objects in detail and gain a better
understanding of the underlying physics.
Now going to have a brief overview of surveys which
can or could be used to study fast temporal
behaviour in various wavebands.
Wednesday 20 January 2010
X-ray/Gamma-ray energies:
Integral
Gamma-ray/X-ray/Optical
(ESA + others), 2002-2012(?)
Wednesday 20 January 2010
X-ray/Gamma-ray energies:
Integral
SGR 1806-20 (magnetar)
Gamma-ray/X-ray/Optical
(ESA + others), 2002-2012(?)
20-100keV
Hurley et al (2005)
Wednesday 20 January 2010
X-ray/Gamma-ray energies:
Integral
SGR 1806-20 (magnetar)
Gamma-ray/X-ray/Optical
(ESA + others), 2002-2012(?)
Swift
Gamma-ray/X-ray/Optical-UV
(NASA with UK involvement),
2004-
RXTE
Gamma-ray/X-ray
(NASA)
1995-2010?
Wednesday 20 January 2010
20-100keV
Hurley et al (2005)
X-ray/Gamma-ray energies:
Integral
Gamma-ray/X-ray/Optical
(ESA + others), 2002-2012(?)
Swift
Gamma-ray/X-ray/Optical-UV
(NASA with UK involvement),
2004-
RXTE
Gamma-ray/X-ray
(NASA)
1995-2010?
Wednesday 20 January 2010
X-ray/Gamma-ray energies:
Integral
Gamma-ray/X-ray/Optical
(ESA + others), 2002-2012(?)
Swift
Gamma-ray/X-ray/Optical-UV
(NASA with UK involvement),
2004-
RXTE
Gamma-ray/X-ray
(NASA)
1995-2010?
Wednesday 20 January 2010
GRO J1655-40 Brocksopp et al (2006)
Future All-Sky High Energy Surveys
Astrosat: Indian satellite with some UK
involvement. All sky monitor.
launch 2010.
Spectrum-RG: Russian satellite with some
UK involvement. All sky monitor.
(LOBSTER) launch ~2012.
Still under development/approval:
Janus (possibly under NASA `super SMEX’)
EXIST (incl 1.1m optical/IR telescope)
both led by USA but with possible UK involvement
Future not that bright in X-rays ....
Wednesday 20 January 2010
Surveys in the radio sky
Pathfinders for SKA ...
LOFAR Dutch +UK involvement
30-80 MHz; 120-240 MHz. All sky and
t<1sec.Opening ceremony July 2010.
MeerKAT South Africa
0.9-1.8 GHz (2013); +8-14GHz (2014);
+0.6-2.5GHz (2016),
field of view ~degrees, <1sec time res.
ASKAP
Wednesday 20 January 2010
Australia + Int partners incl UK
0.7-1.8 GHz, 30 square degree FoV,
beta phase 2011, full phase 2013.
High time resolution.
Square Kilometer Array (SKA)
International Project.
Cost ~1.5 billion euros.
Location: Australia or South Africa
Phase 1: start 2016?
Frequency Range: 100 MHz-25GHz.
Field of View: 1 square degree at 1.5GHz;
200 sq degrees at 0.7GHz;
Time resolution: <100 nsec
Future seems bright at radio wavelengths ....
Wednesday 20 January 2010
Science Areas (some random examples)
Radio emission from exo-planets
Wednesday 20 January 2010
Science Areas (some random examples)
Radio emission from exo-planets
Radio emission from Jupiter type
systems very low frequency
radio emission (LOFAR).
Wednesday 20 January 2010
Science Areas (some random examples)
Radio emission from exo-planets
Wednesday 20 January 2010
Science Areas (some random examples)
Radio emission from exo-planets
Radio emission from Terrestrial
planets. Electron Cyclotron
Maser Emission (polarised).
Frequency depends on B field.
Expected to be GHz plus.
Although ALMA will have small
view its frequency range will be
well placed to identify this
emission.
Wednesday 20 January 2010
Science Areas (some random examples)
Radio emission from exo-planets
Wednesday 20 January 2010
Science Areas (some random examples)
Radio emission from exo-planets
Willes & Wu (2005)
Wednesday 20 January 2010
Science Areas (some random examples)
Radio emission from exo-planets
Wednesday 20 January 2010
Science Areas (some random examples)
Radio emission from exo-planets
Signatures of planets expected to be short duration
but highly polarised.
Wednesday 20 January 2010
Short Bursts from Extra-Galactic Sources
Lorimer et al (2007)
Parkes 64m radio dish. Burst lasted <5ms and had
a 30 Jy dispersed flux. Thought to be at cosmological
distance. No gamma-ray event. Coalescence of neutron
stars? SKA should discover many such events.
Wednesday 20 January 2010
Optical/IR Surveys
not a comprehensive overview!
Requirements: wide field of view;
relatively high cadence of operations.
RAPTOR: USA
Two small telescopes separated by 20 miles.
Faint limit ~12mag; FoV 1500 square degrees.
www.raptor.lanl.gov
Wednesday 20 January 2010
Optical/IR Surveys
not a comprehensive overview!
Requirements: wide field of view;
relatively high cadence of operations.
RAPTOR: USA
Two small telescopes separated by 20 miles.
Faint limit ~12mag; FoV 1500 square degrees.
Shows that fast transients could be caught by small
telescopes
www.raptor.lanl.gov
Wednesday 20 January 2010
‘Pi of the sky’ Polish
Two 85mm lenses, located in Las Campanas, Chile
Real time analysis for transients
grb.fuw.edu.pl
Wednesday 20 January 2010
‘Pi of the sky’ Polish
Two 85mm lenses, located in Las Campanas, Chile
grb.fuw.edu.pl
Wednesday 20 January 2010
‘Pi of the sky’ Polish
Two 85mm lenses, located in Las Campanas, Chile
Solokowski (2007)
A number of very short (<1min)duration transients
grb.fuw.edu.pl
Wednesday 20 January 2010
Super-Wasp
UK
Two facilities, one in La Palma, one in South Africa.
Main aim exo-planets, but also detects transients.
Wednesday 20 January 2010
Super-Wasp
Wednesday 20 January 2010
UK
Super-Wasp
UK
Courtesy: George Marshall
Warwick
To date 17 clear examples of short duration, large
flare events. Flare stars? CV outbursts?
Wednesday 20 January 2010
Surveys with larger Telescopes
Field of view smaller compared to previous surveys.
Series of short exposure on same field or cover
sky as quickly as possible.
RaTS: Rapid Temporal Survey
Isaac Newton Telescope
Science Goal: Discover new
ultra-compact binary systems.
A series of 30 sec exposures
of same field for 2-3 hrs.
Ramsay & Hakala (2005)
Wednesday 20 January 2010
Surveys with larger Telescopes
Field of view smaller compared to previous surveys.
Series of short exposure on same field or cover
sky as quickly as possible.
Wednesday 20 January 2010
Surveys with larger Telescopes
Field of view smaller compared to previous surveys.
Series of short exposure on same field or cover
sky as quickly as possible.
Ultra-Compact Binaries (AM CVn systems).
Binary orbital periods less than ~70mins.
Wednesday 20 January 2010
Surveys with larger Telescopes
Field of view smaller compared to previous surveys.
Series of short exposure on same field or cover
sky as quickly as possible.
Wednesday 20 January 2010
Surveys with larger Telescopes
Field of view smaller compared to previous surveys.
Series of short exposure on same field or cover
sky as quickly as possible.
KL Dra: Outbursts every 2 months. Optical
and the UV. ~3 mag. Rapid rise. Ramsay et al (2010)
Wednesday 20 January 2010
Surveys with larger Telescopes
Field of view smaller compared to previous surveys.
Series of short exposure on same field or cover
sky as quickly as possible.
Wednesday 20 January 2010
Surveys with larger Telescopes
Field of view smaller compared to previous surveys.
Series of short exposure on same field or cover
sky as quickly as possible.
Predicted for systems to experience a large
scale-outburst as the systems age. Predicted
to be several 1000/yr down to V~24. (Bildsten et al (2007)
Wednesday 20 January 2010
Surveys with larger Telescopes
Field of view smaller compared to previous surveys.
Series of short exposure on same field or cover
SN.1a’s
sky as quickly as possible.
Predicted for systems to experience a large
scale-outburst as the systems age. Predicted
to be several 1000/yr down to V~24. (Bildsten et al (2007)
Wednesday 20 January 2010
VST and VISTA
4m, Paranal, ESO/UK
VLT Survey Telescope (VST)
Wednesday 20 January 2010
www.vista.ac.uk/
vstportal.oacn.inaf.it/
2.6m, Paranal, ESO/Italy
Visible & Infrared Survey Telescope
for Astronomy (VISTA)
VST and VISTA
4m, Paranal, ESO/UK
VLT Survey Telescope (VST)
VST Surveys
Wednesday 20 January 2010
www.vista.ac.uk/
vstportal.oacn.inaf.it/
2.6m, Paranal, ESO/Italy
Visible & Infrared Survey Telescope
for Astronomy (VISTA)
VST and VISTA
4m, Paranal, ESO/UK
VLT Survey Telescope (VST)
Wednesday 20 January 2010
www.vista.ac.uk/
vstportal.oacn.inaf.it/
2.6m, Paranal, ESO/Italy
Visible & Infrared Survey Telescope
for Astronomy (VISTA)
VST and VISTA
4m, Paranal, ESO/UK
VLT Survey Telescope (VST)
VISTA Surveys
Wednesday 20 January 2010
www.vista.ac.uk/
vstportal.oacn.inaf.it/
2.6m, Paranal, ESO/Italy
Visible & Infrared Survey Telescope
for Astronomy (VISTA)
PanStarrs:
USA led, UK involvement
Four 1.8m telescopes (Hawaii) . Each 3 square degree
field. 6000 sq degrees every night. 30-60sec exposures.
V~24. First telescope taking data now.
pan-starrs.ifa.hawaii.edu/public/
Wednesday 20 January 2010
PS1
PanStarrs:
USA led, UK involvement
Four 1.8m telescopes (Hawaii) . Each 3 square degree
field. 6000 sq degrees every night. 30-60sec exposures.
V~24. First telescope taking data now.
pan-starrs.ifa.hawaii.edu/public/
LSST:
USA
8.4m telescope in Chile. ~10 square degree FoV.
Short exposures. Timescales as short as 1 min
expected to be probed. Single image depth
r~24-25. First light 2015.
www.lsst.org
Wednesday 20 January 2010
PS1
How it might look
PanStarrs:
USA led, UK involvement
Four 1.8m telescopes (Hawaii) . Each 3 square degree
field. 6000 sq degrees every night. 30-60sec exposures.
V~24. First telescope taking data now.
pan-starrs.ifa.hawaii.edu/public/
LSST:
PS1
USA
8.4m telescope in Chile. ~10 square degree FoV.
Short exposures. Timescales as short as 1 min
expected to be probed. Single image depth
r~24-25. First light 2015.
www.lsst.org
How it might look
Both have the potential to discover many fast
transients. However, cautionary tale from
Deep Lens Survey .....
Wednesday 20 January 2010
Deep Lens Survey
100 nights on NOAO Blanco and
Mayall 4m Telescopes. Observed 5
4 square degree fields to study
weak gravitational lensing.
Found many solar system objects and
many transients (many flare stars).
dls.physics.ucdavis.edu
Wednesday 20 January 2010
Deep Lens Survey
100 nights on NOAO Blanco and
Mayall 4m Telescopes. Observed 5
4 square degree fields to study
weak gravitational lensing.
Found many solar system objects and
many transients (many flare stars).
dls.physics.ucdavis.edu
Wednesday 20 January 2010
Deep Lens Survey
100 nights on NOAO Blanco and
Mayall 4m Telescopes. Observed 5
4 square degree fields to study
weak gravitational lensing.
Found many solar system objects and
many transients (many flare stars).
Becker et al (2004)
dls.physics.ucdavis.edu
Wednesday 20 January 2010
Deep Lens Survey
100 nights on NOAO Blanco and
Mayall 4m Telescopes. Observed 5
4 square degree fields to study
weak gravitational lensing.
Found many solar system objects and
many transients (many flare stars).
Two transients appeared extra-galactic:
one extended and one near galaxy.
However, followup observations showed
they too were late-type M dwarfs.
Upshot - deep transients surveys
Becker et al (2004)
are going to have trouble identifying
the `interesting’ sources.
Kulkarni & Rau (2006) suggest late-type flare stars 2 orders magnitude
more common than extra-galactic transients.
dls.physics.ucdavis.edu
Wednesday 20 January 2010
Gravitational Radiation
 Compact binary inspiral: “chirps”
» NS-NS waveforms are well described
» BH-BH need better waveforms
» search technique: matched templates
 Supernovae / GRBs:
“bursts”
» burst signals in coincidence with signals in
electromagnetic radiation
» prompt alarm (~ one hour) with neutrino detectors
Wednesday 20 January 2010
Gravitational Radiation
 Compact binary inspiral: “chirps”
» NS-NS waveforms are well described
» BH-BH need better waveforms
» search technique: matched templates
 Supernovae / GRBs:
“bursts”
» burst signals in coincidence with signals in
electromagnetic radiation
» prompt alarm (~ one hour) with neutrino detectors
Wednesday 20 January 2010
Gravitational Radiation
 Compact binary inspiral: “chirps”
» NS-NS waveforms are well described
» BH-BH need better waveforms
» search technique: matched templates
 Supernovae / GRBs:
“bursts”
» burst signals in coincidence with signals in
electromagnetic radiation
» prompt alarm (~ one hour) with neutrino detectors
Wednesday 20 January 2010
Gravitational Radiation
 Compact binary inspiral: “chirps”
» NS-NS waveforms are well described
» BH-BH need better waveforms
» search technique: matched templates
 Supernovae / GRBs:
“bursts”
» burst signals in coincidence with signals in
electromagnetic radiation
» prompt alarm (~ one hour) with neutrino detectors
Detection of gravitational radiation will open up
a whole new window on the universe.
Wednesday 20 January 2010
Gravitational Radiation
 Compact binary inspiral: “chirps”
» NS-NS waveforms are well described
» BH-BH need better waveforms
» search technique: matched templates
 Supernovae / GRBs:
“bursts”
» burst signals in coincidence with signals in
electromagnetic radiation
» prompt alarm (~ one hour) with neutrino detectors
Detection of gravitational radiation will open up
a whole new window on the universe.
Need to identify transient sources which cause
burst of gravitational radiation preferably before
they do.
Wednesday 20 January 2010
Final thoughts...
- Information and expertise should be shared;
- Identify moving objects and dwarf flare stars;
- Real time identifications of fast transients needs
to be made robust to allow ...
- Rapid followup observations at different energies
if we are to determine the nature many of these fast
transients.
Wednesday 20 January 2010