SERGIO CAMPANA SWIFT FOLLOW UP OF GW150914

Transcription

1 SERGIO CAMPANA SWIFT FOLLOW UP OF GW150914

2 Detecting Area CdZnTe Operation Photon Counting 2.0 sr (partially coded) Detection Elements Size 256 modules of 128 elements 4mm x 4mm x 2mm PSF 17 arcminutes Location Accuracy 1-4 arcminutes Energy Range kev Burst Detection Rate >100 bursts/year Effective Area Operation Detection Element Pixel Scale PSF Location Accuracy Energy Range Sensitivity Wolter I XMM EPIC CCD kev Photon Counting, Integrated Imaging, & Rapid Timing 23.6 x 23.6 arcminutes 600 x 600 pixels 2.36 arcsec/pixel 18 arcsec 1.5 kev 3-5 arcseconds kev 2 x ergs cm-2 s-1 in 104 sec ultraviolet/optical telescope F-number on t 1-4 arcminutes Energy Range kev BuRst alert telescope Burst Detection Rate Modified Ritchey-Chrétien 30 cm diameter 12.7 >100 bursts/year Detecting Area Operation Effective Area Operation Detection Elements Size Detection Element PSF Pixel Scale Location Accuracy PSF Location Accuracy Energy Range Energy Range Burst Detection Rate Sensitivity The Mission Operations Ce Coded Mask University provides real-ti 2 spacecraft and moni of the 5200 cm X-R a y t e l e s C o p e also taking care of scien Wolter I Targets of Opportunity ( CdZnTe capture and accounting. T XMM EPIC CCD Photon Counting ground station at Malin kev primary communications. S 2.0 sr (partially coded) characteristics are relaye Photon Counting, Integrated through the NASA TDRSS Imaging, & Rapid Timing 256 modules of 128 elements for rapid distribution to the 23.6 x 23.6 arcminutes 4mm x 4mm x 2mm 600 x 600 pixels Swift data will be made ava different data centers locat 17 arcminutes 2.36 arcsec/pixel High Energy Astrophysics kev arcminutes 18 arcsec Center, HEASARC), the UK Center, UKSSDC), and Ital 3-5 arcseconds Center, kev ISAC) kev >100 bursts/year 2 x ergs cm-2 s-1 in 104 sec The Swift Science Center The Mission The Mission Operations Center (MOC) at Penn State community University in fully utilizing p University provides real-time command and control data analysis tools for Swif responsible for coordinatin of the space a y pt Ceol p u l t R a v ixo-l ert /o t ieclae l st e sec o p e of the spacecraft and monitors the observatory, while also taking care of science and mission planning, X-Ray telescope C atching g amma -R ay B ursts 5200 cm2 F ly... Coded Mask B ursts on the BuRst alert telescope Targets of Opportunity (ToO) handling, and data F-number capture and accounting. The Italian Space Agency s Effective Area provides the ground station at Malindi, Kenya Operation primary communications. Swift burst alerts and burst Operation characteristics are relayed almost instantaneously through the NASA TDRSS space data link to the GCN FieldDetection of View Element for rapid distribution to the community. PSF Detection Element Location Accuracy to the world via Swift data will be made available three Pixel Scale Wavelength Range (the different data centers located in the United States PSF High Energy Astrophysics Science Archive Research Colors amma -R ay F ly... on the B ursts mma -R ay W H AT I S S W I F T Location Accuracy Center, HEASARC), the UK (the UK Swift Science Data Location Accuracy Spectral Resolution (Grisms) Center, UKSSDC), and Italy (the Italian Swift Archive Sensitivity Energy Range Center, ISAC). Pixel Scale Sensitivity Limitthe science The Swift Science Center (SSC)Bright assists takings team and also the Italian Modified Ritchey-Chrétien Targets of Wolter I develop data analysis tools respectively.capture The Swiftand Sci 30 cm diameter XMM EPIC CCD for developing the UVOT to ground sta kev primary com Intensified CCD timeline of BuRst characteristi PhotonPhoton Counting, Integrated Counting time (sec ) through the Imaging, & Rapid Timing 17 x 17 arcminutes 0 for rapid GRBdis det 23.6x x arcminutes 2048 pixels xnm pixels 0.3 arcseconds 2.36 arcsec/pixel 170 nm nm 18 arcsec 1.5 kev nm arcseconds λ/δλ ~ B = 24 in white light in sec - 10 kev 0.48 arcseconds 2 x ergs cm-2 s-1 in 104 sec mv = 7 mag Slew be Swift data w BAT app different dat GRB acq ~ 50 High Energy 70 XRT loca Center, HEAS 240 UVOT fin Center, UKS 300 Center, ISAC XRT ligh 1200 XRT spe The Swift S All autom ~ 60,000 complet community community in fully utilizing the Swift data. It is also responsible responsible for coordinating the development u l t R a vof i othe let/optical telescope data analysis tools for Swift data. The BAT instrument Modified Ritchey-Chrétien team and the Italian Swift Archive Center will 30 cm diameter develop data analysis tools for the BAT and XRT data data analysi respectively. The Swift Science Center is responsible F-number for developing the UVOT tools. for developin 12.7 Intensified CCD team and develop data respectively.

3 GW WITH SWIFT Swift follow-up of the Gravitational Wave source GW P.A. Evans 1?, J.A. Kennea 2, S.D. Barthelmy 3, A.P. Beardmore 1, D. N. Burrows 2, S. Campana 4, S.B. Cenko 3,5, N. Gehrels 3, P. Giommi 6, C. Gronwall 2,7, F. E. Marshall 3, D. Malesani 8, C.B. Markwardt 3,9, B. Mingo 1, J. A. Nousek 2, P. T. O Brien 1, J. P. Osborne 1, C. Pagani 1, K.L. Page 1, D.M. Palmer 10, M. Perri 6,11, J. L. Racusin 3, M.H. Siegel 2, B. Sbarufatti 2,4, G. Tagliaferri 4 1 Department of Physics and Astronomy, University of Leicester, Leicester, LE1 7RH, UK LIB skymap Evans et al LIB convolved with galaxies Swift probability map LAL inference

4 4 T Evans WO et al. P O I N T I N G M O D E S As well as the checks performed to automatically rank each XRT source, the 2MASS catalogue (Skrutskie et al. 2006) and SIMBAD database (Wenger et al. 2000) were automatically searched, and any sources within the 3-s XRT error region were identified. This information was not used to determine the source rank, but to inform human decisions as to the nature of the source. It is important to note that this spatial correlation does not necessarily mean that the XRT source and the 2MASS/SIMBAD object are the same thing: Evans et al. (2014) showed that 11% of XRT sources with SIMBAD matches, and 64% of those with 2MASS matches are not related but chance alignments. An automated pipeline was built to search for candidate counterparts in the UVOT observations using standard HEASOFT analysis tools. In the pipeline the tool UVOTDETECT was used to search for sources in the sky image files. For each observation searches were made using the longest exposure and the sum of all images if the summed exposure was significantly longer than the longest exposure. Candidate sources whose images were not star-like or were too close to other sources were rejected. Sources without counterparts in the USNO-B1.0 catalogue (Monet et al. 2003) or Hubble Guide Star Catalog (Lasker et al. 2008) were considered possible candidates. The UVOT image near each of these possible candidates was then visually compared with the corresponding region in the Digitized Sky Survey. This visual comparison was used to reject candidates due to readout streaks or ghost images of bright sources. The UVOT images near Rank 1 or Rank 2 XRT sources were also examined and compared with the DSS. UVOT source magnitudes or upper limits were determined using the tool UVOTSOURCE. 5 pointings on high probability regions ~1,000 s exposure Sep tile automatic 1.1o radius exposure This involved comparing ours source detections with the ROSAT All Sky Survey (RASS; Voges et al. 1999). To do this we assumed a typical AGN spectrum, a power-law with hydrogen column density 17of G = 1.7. These ranks N = 3 10 cm andsep a photon index Figure 2. The XRT exposure map of the 37-point tiled observations of the LMC performed with Swift, demonstrating the structure of the pattern. The black lines are the vetoed columns on the CCD. The cyan circle has radius of 1.1 and is shown for reference. Axis are RA and Dec, J2000. H 20 2 were defined as follows: Rank 1: Good GW counterpart candidate. Sources which lie within 2% of LIB

5 RESULTS 5 initial pointings: < ct s 1, < erg cm 2 s 1 LMC tiling: < ct s 1, < erg cm 2 s 1 < erg s LMC Observation in u-band XRT No transient brighter than - 5 pointings u AB < LMC u AB <18.8 UVOT Table 2. Sources detected by Swift-XRT in follow-up of GW150914, with u-band magnitudes from UVOT. RA Dec Error Flux u Magnitude Catalogued name (J2000) (J2000) 90% conf kev, erg cm 2 s 1 AB mag 09h 14m 06.54s (1.9 ± 0.5) N/A XMMSL1 J h 13m 30.24s (5.3 ± 2.0) ±0.02 a ESO = 1RXS J h 17m 60.62s (8.9 ± 2.4) ±0.05 1RXS J

6 SWIFT STRATEGY Table 1. Completeness of the GWGC, based on fig. 5 of White et al. (2011). Motivated by short GRBs Distance (Mpc) Completeness ( per cent) Convolve LIB with GWGC galaxy catalog - ASAP search for an on-axis short GRB afterglow >100 0 a Note. a The GWGC only includes galaxies within 100 Mpc, hence the sudden cut-off. short s observations - days after search for an off-axis orphan longer 500 s observations Evans et al. 2015

7 DETECTABILITY 10 deg opening angle

8 CONCLUSIONS Swift is the only sensitive soft X-ray and UV facility able to search for a GW counterpart (as well as a large FOV hard X- ray detector, BAT) Immediate search with short s exposures looking for a short GRB afterglow (ALV+galaxy) Late time search (days) with long 1,000 s exposures looking for an orphan GRB afterglow (ALV+galaxy) Italian involvement: Swift team members & connections with GRAWITA