Transcript For rate - Agenda INFN

Gravitational Wave-related projects at OAR
Virgo/LIGO + eLISA Sources
Multimessenger follow up
Instrumentation
Virgo EGO Science Forum (VESF)
Luigi Stella
(with thanks to Enzo Brocato and
Marica Branchesi for several slides)
Double White Dwarf Binaries (AM CVn-like)
Nov 2002
Nov 2001
RXJ0806.3+1527: a double degenerate binary
system (2WDs) with an orbital period of 5.4min !!
One of the best target for gravitational wave
Detection by eLISA
Magnetars: Bursts
-
energy release ~1038-1041 ergs
subsecond duration
often emitted in bunches
SGR 1806-20: Giant Flare of 2004 Dec 27
(Palmer et al. 2005
Hurley et al. 2005)
Moon reverberation seen !
(Mereghetti et al. 2005)
The B-field of Magnetars
Very strong internal B-fields in a newborn differentially rotating fast-spinning neutron star
For initial spin periods of Pi∼1–2 ms, differential rotation can store ∼1052(Pi/1 ms)2 ergs,
that can be converted into a magnetic field of up to 3x1017 (Pi/1ms)-1 G.
(efficient dynamo might be limited to ~3x1016 G)
(Duncan & Thompson 1992)
Bt
Bd
Fast spin (few ms) and
differential rotation generate
internal toroidal field B > 1015 G
Bd ~ 1014-15 G outer dipole field (spin-down, pulsations)
inferred from spin-down rate (and confirmed through the
energetics and fast variability properties of the “ringing tail”
of Giant Flares from SGRs)
Bt > 1015 G
inner toroidal field (energy reservoir):
lower limit from: L(persistent) x age ~ 1047 ergs
Newborn Magnetars as Gravitaional Wave Sources
~ 1 week, ~ 108cycles
2x1016 G
6x1016 G
(for Virgo Cluster distance, 20 Mpc)
- GW signal at ~1 kHz evolving in 1 week
- Consider initial spin period of 2ms
Most promising region is
Bt > 1016.5 G and Bd < 1014 G
- Required no. of templates is very large
Expected magnetar birth rate in the ~2000 galaxies of Virgo: ~ 1 yr-1 !
Potentially Very Interesting GW Event Rate in Advanced LIGO/Virgo-class instruments
Short Gamma-Ray Bursts
•
GRBs duration distribution is
bimodal
(e.g. Briggs et al.
2002)
– 0.1-1 s -> Short bursts
– 10-100 s -> Long bursts
•
Short GRBs are harder than
long GRBs
(e.g. Fishman & Meegan, 1995;Tavani 1996).
GRB970228: the 1st X-ray and Optical afterglow
•
•
Fast follow up with the
BeppoSAX-NFIs (8hr) led to the
discovery of a bright unknown Xray source.
A second pointing 3 days after
showed that source had faded.
(Costa, et al., 1997)
• Accurate (~1 arcmin) X-ray position led
to the identification of a fading optical
source from ground based telescopes
(Van Paradijs, et al., 1997)
(Pedichini et al 1997)
GRB970508: the 1st redshift
•
•
Images in the 2-10 keV range by the BSAX WFC (10-200 sec after the GRB) and by
the BSAX MECS (6 hrs and 3 days).
The BSAX observation led the Caltech group to the measurement of the first
redshift and Frail et al to the discovery of the 1st radio afterglow and direct
measurement of relativistic expansion
GRBs have:
X-ray afterglows > 90%
Optical afterglows ~ 40% - 50%
Radio afterglows ~ 35% - 40%
Metzeger et al., 1997
Long GRBs: cosmological distances !
Swift
Instrumentation
Burst alert telescope (BAT) 10-150 keV
X-ray telescope (XRT) 0.3-10 keV
UV-optical telescope (UVOT) U-I
- USA, I, UK mission
dedicated to GRB Science
1.
2.
3.
4.
Burst Alert Telescope triggers on GRB, calculates position to < 4 arcmin
Spacecraft autonomously slews to GRB position in 20-70 s
X-ray Telescope determines position to < 5 arcseconds
UV/Optical Telescope images field, transmits finding chart to ground
BAT Burst Image
T<10 s,  < 4'
XRT Image
UVOT Image
BAT Error
Circle
T<100 s,  < 5''
T<300 s
Host Galaxies of Short GRBs
- Short GRBs are located inside or close to early type galaxies with low star
formation activity, BUT some are found in galaxies with star formation
activity.
GRB050509b
GRB050709
- Short GRBs are NOT associated to Supernovae
- Short GRB are at cosmological distances but at smaller redshifts
than Long GRBs
- Short GRB are ~100 times less energetic than Long GRBs
Coalescing binary models
Association of Short GRBs to low SFR galaxies + absence of SN :
Long delay (Gyrs) between the formation of the neutron star (or black hole) and the
Short GRB explosion.
Merging (or Coalescing) binary models for Short GRBs
Neutron Star + Neutron star (NS-NS) or Neutron Star + Black hole (NS-BH)
Strong Gravitational Wave Sources !
To summarise
-
Newborn Magnetars are interesting GW sources for Advanced
LIGO/Virgo-class instruments.
Newborn magnetars can be detectable from the
whole Virgo Cluster, where their birth rate is ~1 magnetar/yr
-
Short Gamma Ray Burst, if (for the most part) due to coalescing
binaries, provide an independent way of estimating the NS-NS and
NS-BH merging and GW detection rates
Evidence that the local Short GRB rate is dominated by NS-NS
and NS-BH binaries formed in globular clusters through
dynamical interactions: this increases the local rate and
chances of detecting GWs from these events
Kilonovae and Radio Flares
Significant mass (0.01-0.1 mo) is dynamically ejected
during NS-NS NS-BH mergers
at sub-relativistic velocity (0.1-0.2 c)
(Piran et al. 2013, MNRAS, 430; Rosswog et al. 2013 , MNRAS, 430)
EM signature similar to Supernovae
Macronova – Kilonova
short lived IR-UV signal (days) powered
by the radioactive decay of heavy
elements synthesized in the ejected
2005, astro-ph0510256;
outflow Kulkarni
Li & Paczynski 1998,ApJL, 507
Metzger et al. 2010, MNRAS, 406;
Piran et al. 2013, MNRAS, 430
RADIO REMNANT
long lasting radio signals (years)
produced by interaction of ejected
sub-relativistic outflow with
surrounding matter Piran et al. 2013, MNRAS, 430
12
Kilonovae Light Curves
Source at distance of 200 Mpc
5
10
15
20
Major uncertainty OPACITY of
“heavy r-process elements”
25
30
0.1
Days
1
10
M/Mo=10-2
New simulations including
lanthanides opacities show:
Luminosity(ergs/s)
1042
Fe-Kilonova, β=0.1
r-process, β=0.1
1041
• broader light curve
• suppression of UV/O emission
and shift to infrared bands
-20
Opacities:
Fe
r-process
-15
Magnitude
Red magnitude
Kilonova model afterglow peaks about
a day after the merger/GW event
NS-BH Piran et al.
NS-NS Piran et al.
Blackbody Metzger. et al.
Fe-Opacity Metzger et al.
-10
- 5
1040
1039
0
2
4 6 8 10 12 14
Days
Barnes & Kasen 2013, ApJ, 775
0
5
1
3 5 7 1 3 5 7
Days
13
The Advanced VIRGO/LIGO Era
- Growing emphasis on the search for the astrophysical counterparts of
candidate gravitational wave (GW) event
- From astrophysically triggered searches to searches triggered by GW
candidate events.
- Astrophysical counterparts required to confirm nature of GW events
Advanced GWdetector era observing scenario
Position uncertainties
with areas of tens to
hundreds of sq. degrees
Summary of plausible observing scenario
LSC & Virgo collaboration
arXiv:1304.0670
aLIGO/Virgo Range
Rate
Localization
18
GRB970228: the 1st X-ray and Optical afterglow
•
•
Fast follow up with the
BeppoSAX-NFIs (8hr) led to the
discovery of a bright unknown Xray source.
A second pointing 3 days after
showed that source had faded.
(Costa, et al., 1997)
• Accurate (~1 arcmin) X-ray position led
to the identification of a fading optical
source from ground based telescopes
(Van Paradijs, et al., 1997)
(Pedichini et al 1997)
- High Energy Satellites:
* Wide field monitors (e.g. Swift), limited sensitivity
* X-ray optical design available (WFXT), but no approved program yet
- Optical/NIR: large field of view instruments needed
* Medium and Large telescopes have instruments < 1deg^2
* Few very small automated large field telescopes (~100 deg^2, R <10-12)
(Tortora, PiSky)
* Dawn of “Time Domain Astronomy”: PTF (1.2 m, 8 deg^2, R<21, 5d),
PanSTaRR (1.8 m, 9 deg^2, R< 22, 1 month)
* End of decade: LSST (8.4 m^2, 10 deg^2, R~24, ¼ sky twice/night)
- Radio:
• VLA, LOFAR, SKA
“Culture” of fast-response follow up observations: available especially in the SN and
GRB communities.
Optical transient sky
Kasliwal 2011, BASI, 39
Exploration of the optical transient sky
at faint magnitudes and short timescale
has started recently, but it is still
unknown..
Optical contaminating transients:
foreground - asteroids, M-dwarf flares,
CVs, Galactic variable stars
background - AGN, Supernovae
For rate see Rau et al. 2009, PASP, 121 and for fast transient
(0.5 hr – 1d) see Berger et al. 2013, ApJ, 779
Transient X-ray and radio sky is less populated than the optical sky
X-ray contaminating transients:
tidal disruption events, AGN variability
Ultra-luminous X-ray Source variability,
background GRBs
For rate in the Advanced LIGO/Virgo Horizon
see Kanner et al. 2013, ApJ, 774
Radio contaminating transients:
Supernovae, AGN variability
For rate see Mooley et al. 2013, ApJ,768
27
Other groups :
PTF - Palomar Transient Factory
8 deg
“The case of GRB 130702A demonstrates
for the first time that optical transients can
be recovered from localization areas of
∼100 deg2, reaching a crucial milestone
on the road to Advanced LIGO.”
Detection limit: R ~ 20.5
Singer et al. 2013:
“We report the discovery of the
optical afterglow of the γ-ray burst
(GRB) 130702A, identified upon
searching 71 deg2 surrounding the
Fermi Gamma-ray Burst Monitor
(GBM) localization.”
INAF (Istituto Nazionale di Astrofisica) decided to
participate in the EM follow-up program
as an Institution
by providing Italian observational resources
and the expertise in time domain astronomy
STEPS for an efficient EM-follow up
Wide-field telescope
FOV >1 sq.degree
• Reference Images
• Observational strategy
• Send data to Image
Analysis Server
VST
Image Analysis Server
“Fast” and “Smart”
software
to select a sample of
candidate counterparts
Candidate
characterization
VLT
LBT
The EM Counterpart of GW!
• Image Analysis is
performed by running
specific pipelines.
• The human intervention
is not yet negligible.
• Spectra vs templates
• Light Curves
• Multi-wavelength
analysis (Near-IR,
Radio, hugh energy
from space, ASTRI,
CTA)
INAF- project: Gravitational Astrophysics
Advisory Board
P.I.: E. Brocato
Working Groups
WP 1
WP 2
WP 3
WP 4
WP 5
• GW
astronomy
• Contact with
LIGO / Virgo
Collaboration
• Search for EM
candidates
• Photometric
software
• Surveys,
Ref. Images
•Characterization
• Spectroscopy
• Light Curves
• Multiwavelegth
observations
• ToO proposals
• Relationship
EU partners
• Space
• Time Domain
Astronomy
• VLT
• NTT
• ESO
telescopes
• Swift
• XMM
• Chandra
• Fermi
• INTEGRAL
• GW physical
information
• EM
Observational
strategies
• Simulations
• VST
• CITE
• Asiago
• TORTORA
• Sicily (tbd)
• LBT
• NOT / TNG (?)
• REM
• AZT-24 (NIR)
• SRT (Radio)
INAF: WIDE-FOV telescopes to cover the GW error box
South America
VST - 2.6 m VLT Survey ESO telescope
 corrected FOV 1 deg x 1 deg, pixel scale of 0.21”/pixel
 1 hour to cover a sky area of 40 sq. deg. in r’ band
reaching a magnitude of about 23
in 2016 the INAF-Guaranteed Time Observation
20% of the total observing VST time
 Public Surveys: Reference Images available
REM (Rapid Eye Mount): 60 cm diameter fast robotic telescope
TORTORA camera (Telescopio Ottimizzato per la
Ricerca dei Transienti Ottici RApidi) FOV 24°x32°,
time resolution 0.1 s, B-limiting magnitude 11
 two cameras can observe simultaneously in optical and
NIR (J, H e K), FOV 10x10 arcmin
INAF: WIDE-FOV telescopes to cover the GW error box
Europe
“Campo Imperatore Transient Experiment”:
60cm Schmidt telescope with a 2 sq. deg. FOV up to
V ~21mag (project to extend to 6 sq. degree)
 near-IR telescope, AZT-24 FoV of 4.4’x4.4’ for characterization
Funds to realize a 1m Telescope (FOV 8 sq. deg) in Sicily
+ SMALLER FOV telescopes like Asiago, Loiano, IRAIT can help during the
search and/or are useful for the characterization
INAF: Characterization of the EM counterparts candidates
North America
Large Binocular Telescope (Arizona)
excellent for characterization,
INAF GTO+ToO (25 % INAF)
 two 8.4 meter primary mirrors
.
 collecting area equivalent to an
11.8-meter circular aperture
 Optical/IR spectrographs
 Large Binocular Camera, FOV 23'x23' , sampling of 0.23”/pixel
South America
Very Large Telescope (VLT, ESO)
• four unit telescopes with main mirrors of 8.2m diameter
•very useful X-shooter spectrograph covering a very wide range of
wavelengths [UV to near infrared] simultaneously
INAF intends to coordinate collaborative ToO proposal
involving other European groups working in the field
INAF: Characterization of the EM counterparts candidates
Canarie
TNG (Telescopio Nazionale Galileo)
 3.58m optical/infrared telescope
 currently optimally equipped for “exoplanet search”
its position could be crucial for the EM-follow up,
few possibilities to set up instruments for this program
NOT (Nordic Optical Telescope 2.5 m) (+ Xshooter?)
good candidate for GW follow-up, thanks to its
good optics and versatile instruments: e.g.
ALFOSC (Andalucia Faint Object Spectrograph and Camera)
 GTO (fraction) + proposal for ToO
INAF:
Radio facilities
INAF radio antennas:
 Medicina (30 m parabolic antenna)
 Noto (32 m parabolic antenna)
 Sardinia Radio Telescope (64 m)
SMALL FOV  characterization
INAF: Space high-energy facilities
From space, INAF can guarantee access - through
submission of regular or DDT proposal starting from
coordinated initiatives of the INAF scientists - to Swift,
XMM, Chandra, Fermi, INTEGRAL.
INAF: Archival search
LBT + VST image archives
ASDC Archive of space missions + ESO data archive
INAF- project: Gravitational Astrophysics
Large FoV (1x1 d)+ mag limits (< 23 m) + High resol. (0.2 p/”)
Characterization: up to 8m class telescopes
Site: southern and northern hemisphere
Wide wavelength coverage: ground based facilities from optical
to radio + high-energy space facilities
 Know-how: Time Domain Astronomy, Observational Strategy,
Image analysis, Accurate Photometry in crowded fields, GRB
astronomy, Data Interpretation, Theoretical models
Collaboration with Virgo teams is crucial
To remain in touch:
https://sites.google.com/site/followupgw/home
VESF – Virgo EGO Science Forum
The scope of VESF is promoting the physics of gravitational
waves, and the collaborations among groups in different
countries
The Forum is intended to be open to scientists in the field of astrophysics,
astroparticle, general relativity, gravitation etc, that may be interested in
the data expected from Virgo and its future upgrades.
VESF presently comprises:
34 groups, 182 members from Virgo, 149 non-Virgo
belonging to European universities, laboratories and
astronomical observatories.
VESF Executive Board.
The executive board is presently composed by
- the EGO director (Federico Ferrini)
- the Virgo spokesperson (Jean-Ives Vinet)
and four members elected by the VESF Council for a period of two years, to
represent the following research areas
-
General Relativity (Nikolaos Stergioulas)
Theoretical Astrophysics and Cosmology (Toni Font)
Observational Astrophysics (Andrea Possenti)
Experimentation in fields related to GW detection not participating to Virgo
(Guglielmo Tino)
The EB elected the VESF Coordinator, choosing in a pool of candidates
proposed by the VESF community (Luigi Stella)
Jan 2014 VESF EB Meeting: proposal of revised VESF Charter sent to VSC