II/342 Hubble Source Catalog (V1 and V2) (Whitmore+, 2016) ================================================================================ Hubble Source Catalog. Whitmore B.C., Allam S.S., Budavari T., Casertano S., Downes R.A., Donaldson T., Fall S.M., Lubow S.H., Quick L., Strolger L.-G., Wallace G., White R.L. =2016AJ....151..134W =2016yCat.2342....0W ================================================================================ ADC_Keywords: Surveys ; Photometry, HST Mission_Name: ESO Keywords: astrometry - catalogs - techniques: photometric - virtual observatory tools Abstract: The Hubble Source Catalog is designed to help optimize science from the Hubble Space Telescope (HST) by combining the tens of thousands of visit-based source lists in the Hubble Legacy Archive (HLA) into a single master catalog. Version 1 of the Hubble Source Catalog includes WFPC2, ACS/WFC, WFC3/UVIS, and WFC3/IR photometric data generated using SExtractor software to produce the individual source lists. The catalog includes roughly 80 million detections of 30 million objects involving 112 different detector/filter combinations, and about 160,000 HST exposures. Source lists from Data Release 8 of the HLA are matched using an algorithm developed by Budavari & Lubow (2012ApJ...761..188B). The mean photometric accuracy for the catalog as a whole is better than 0.10mag, with relative accuracy as good as 0.02mag in certain circumstances (e.g., bright isolated stars). The relative astrometric residuals are typically within 10mas, with a value for the mode (i.e., most common value) of 2.3mas. The absolute astrometric accuracy is better than 0.1" for most sources, but can be much larger for a fraction of fields that could not be matched to the PanSTARRS, SDSS, or 2MASS reference systems. In this paper we describe the database design with emphasis on those aspects that enable the users to fully exploit the catalog while avoiding common misunderstandings and potential pitfalls. We provide usage examples to illustrate some of the science capabilities and data quality characteristics, and briefly discuss plans for future improvements to the Hubble Source Catalog. Description: The HSC v1 contains members of the WFPC2, ACS/WFC, WFC3/UVIS and WFC3/IR Source Extractor source lists from HLA version DR8 (data release 8). The crossmatching process involves adjusting the relative astrometry of overlapping images so as to minimize positional offsets between closely aligned sources in different images. After correction, the astrometric residuals of crossmatched sources are significantly reduced, to typically less than 10mas. The relative astrometry is supported by using Pan-STARRS, SDSS, and 2MASS as the astrometric backbone for initial corrections. In addition, the catalog includes source nondetections. The crossmatching algorithms and the properties of the initial (Beta 0.1) catalog are described in Budavari & Lubow (2012ApJ...761..188B). The HSC v2 contains members of the WFPC2, ACS/WFC, WFC3/UVIS and WFC3/IR Source Extractor source lists from HLA version DR9.1 (data release 9.1). The crossmatching process involves adjusting the relative astrometry of overlapping images so as to minimize positional offsets between closely aligned sources in different images. After correction, the astrometric residuals of crossmatched sources are significantly reduced, to typically less than 10mas. The relative astrometry is supported by using Pan-STARRS, SDSS, and 2MASS as the astrometric backbone for initial corrections. In addition, the catalog includes source nondetections. The crossmatching algorithms and the properties of the initial (Beta 0.1) catalog are described in Budavari & Lubow (2012ApJ...761..188B). Hubble Source Catalog Acknowledgement: Based on observations made with the NASA/ESA Hubble Space Telescope, and obtained from the Hubble Legacy Archive, which is a collaboration between the Space Telescope Science Institute (STScI/NASA), the Space Telescope European Coordinating Facility (ST-ECF/ESAC/ESA) and the Canadian Astronomy Data Centre (CADC/NRC/CSA). File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file hsc1.sam 396 1000 Hubble Source Catalog V1, sample output (on a total of 101,789,844 sources) hsc2.sam 396 1000 Hubble Source Catalog V2, sample output (on a total of 383,834,027 sources) -------------------------------------------------------------------------------- See also: B/hst : HST Archived Exposures Catalog (STScI, 2007) Byte-by-byte Description of file: hsc1.sam hsc2.sam -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 9 A9 --- CatID Unique identifier for each catalog entry (CatID) 11- 21 F11.7 deg RAdeg Right Ascension for the match (J2000) (MatchRA) 23- 33 F11.7 deg DEdeg Declination for the match (J2000) (MatchDec) 35- 42 A8 --- MatchID Identifier for the match (MatchID) 44- 46 I3 --- MemID Unique identifier for each source of a match (MemID) 48- 60 A13 --- Source Source identifier from white light (detection) image (SourceID) 62- 68 A7 --- ImageID Identifier of the image (ImageID) 70 A1 --- Det [Y/N] Is source detected in this observation ? (Det) 72- 82 F11.7 deg RASdeg Right Ascension for this source detection (J2000) (SourceRA) 84- 94 F11.7 deg DESdeg Declination for this source detection (J2000) (SourceDec) 96-107 F12.7 mas Dist Distance from source position to the match position (D) 109-120 F12.7 mas e_Dist Standard deviation of the distance (D) between source and match positions (DSigma) 122 A1 --- AbsCorr [Y/N] Was absolute astrometry correction made? (AbsCorr) 124-131 F8.3 pix XImage ? X position of source in image coordinates (XImage) 133-140 F8.3 pix YImage ? Y position of source in image coordinates (YImage) 142-170 A29 --- ImageName HLA image name (ImageName) 172-176 A5 --- Inst Name of instrument (Instrument) 178-187 A10 --- Mode Observing mode (Mode) 189-197 A9 --- DetID Detector (Detector) 199-213 A15 --- Aperture Aperture (Aperture) 215-222 F8.2 s ExpTime Exposure time (ExposureTime) 224-246 A23 --- TimeS Observation start time (YYYY-MM-DD hh:mm:ss.sss) (StartTime) 248-270 A23 --- TimeE Observation stop time (YYYY-MM-DD hh:mm:ss.sss) (StopTime) 272-281 F10.4 d MJDS Observation start time in MJD (StartMJD) 283-292 F10.4 d MJDE Observation stop time in MJD (StopMJD) 294-301 F8.2 0.1nm lambda Pivot wavelength (WaveLength) 303-308 A6 --- Filter Filter (Filter) (1) 310-339 A30 --- TargetID Target Name for this observation (TargetName) 341-352 E12.6 ct/s FluxAper2 ? Count rate in Filter with an aperture radius 0.3" (WFPC2), 0.15" (ACS, WFC3/UVIS) and 0.45" (WFC3/IR) (FluxAper2) 354-361 F8.3 mag magAper2 ? Magnitude (AB) in Filter an aperture radius 0.3" (WFPC2), 0.15" (ACS, WFC3/UVIS) and 0.45" (WFC3/IR) (MagAper2) 363-371 F9.5 mag magAuto ? Estimated total magnitude in Filter using Source Extractor algorithm (MagAuto) 373-377 A5 --- PropID HST proposal number (PropID) 379-385 F7.3 mag CI ? Concentration Index - difference between magnitude in small and large apertures (CI) 387-393 F7.3 pix RadKron ? Mean value of the Kron Radius from Source Extractor (KronRadius) 395-396 A2 --- Flags Bit encoded flag (Flags) (2) -------------------------------------------------------------------------------- Note (1): Filters: ACS : F435W, F475W, F502N, F550M, F555W, F606W, F625W, F658N, F660N, F775W, F814W, F850LP WFPC2 : F1042M, F122M, F160BN15, F160BW, F170W, F185W, F218W, F255W, F300W, F336W, F343N, F375N, F380W, F390N, F410M, F437N, F439W, F450W, F467M, F469N, F487N, F502N, F547M, F555W, F569W, F588N, F606W, F622W, F631N, F656N, F658N, F673N, F675W, F702W, F785LP, F791W, F814W, F850LP, F953N WFC3 : BLANK, F098M, F105W, F110W, F125W, F126N, F127M, F128N, F130N, F132N, F139M, F140W, F153M, F160W, F164N, F167N, F200LP, F218W, F225W, F275W, F280N, F300X, F336W, F343N, F350LP, F373N, F390M, F390W, F395N, F410M, F438W, F467M, F469N, F475W, F475X, F487N, F502N, F547M, F555W, F600LP, F606W, F621M, F625W, F631N, F645N, F656N, F657N, F658N, F665N, F665N_F6, F673N, F680N, F689M, F763M, F775W, F814W, F845M, F850LP, F953N, FQ232N, FQ243N, FQ378N, FQ387N, FQ422M, FQ436N, FQ437N, FQ492N, FQ508N, FQ575N, FQ619N, FQ634N, FQ672N, FQ674N, FQ727N, FQ750N, FQ889N, FQ906N, FQ924N, FQ937N Note (2): Bit encoded flag as follows:, 0 = point source 1 = extended 4 = saturated -1 = not analyzed -------------------------------------------------------------------------------- History: From https://archive.stsci.edu/hst/hsc Acknowledgements: Hubble Source Catalog Acknowledgement : Based on observations made with the NASA/ESA Hubble Space Telescope, and obtained from the Hubble Legacy Archive, which is a collaboration between the Space Telescope Science Institute (STScI/NASA), the Space Telescope European Coordinating Facility (ST-ECF/ESAC/ESA) and the Canadian Astronomy Data Centre (CADC/NRC/CSA). ================================================================================ (End) Patricia Vannier [CDS] 05-Oct-2016