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.
<Astron. J. 151, 134 (2016)>
=2016AJ....151..134W 2016AJ....151..134W
=2016yCat.2342....0W 2016yCat.2342....0W
ADC_Keywords: Surveys ; Photometry, HST
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 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 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 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:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
hsc1.sam 396 1000 Hubble Source Catalog V1 ( 101,789,844 sources)
hsc2.sam 396 1000 Hubble Source Catalog V2 ( 383,834,027 sources)
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See also:
B/hst : HST Archived Exposures Catalog (STScI, 2007)
Byte-by-byte Description of file: hsc1.sam hsc2.sam
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Bytes Format Units Label Explanations
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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)
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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
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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