J/AJ/154/199 SMASH: Survey of the MAgellanic Stellar History (Nidever+, 2017)
SMASH: Survey of the MAgellanic Stellar History.
Nidever D.L., Olsen K., Walker A.R., Vivas A.K., Blum R.D., Kaleida C.,
Choi Y., Conn B.C., Gruendl R.A., Bell E.F., Besla G., Munoz R.R.,
Gallart C., Martin N.F., Olszewski E.W., Saha A., Monachesi A., Monelli M.,
de Boer T.J.L., Johnson L.C., Zaritsky D., Stringfellow G.S.,
van der Marel R.P., Cioni M.-R.L., Jin S., Majewski S.R.,
Martinez-Delgado D., Monteagudo L., Noel N.E.D., Bernard E.J., Kunder A.,
Chu Y.-H., Bell C.P.M., Santana F., Frechem J., Medina G.E., Parkash V.,
Navarrete J.C.S., Hayes C.
<Astron. J., 154, 199 (2017)>
=2017AJ....154..199N 2017AJ....154..199N (SIMBAD/NED BibCode)
ADC_Keywords: Magellanic Clouds ; Populations, stellar ; Surveys
Keywords: galaxies: dwarf -
galaxies: individual (Large Magellanic Cloud,
Small Magellanic Cloud) - Local Group - Magellanic Clouds - surveys
Abstract:
The Large and Small Magellanic Clouds are unique local laboratories
for studying the formation and evolution of small galaxies in
exquisite detail. The Survey of the MAgellanic Stellar History (SMASH)
is an NOAO community Dark Energy Camera (DECam) survey of the Clouds
mapping 480 deg2 (distributed over ∼2400 square degrees at ∼20%
filling factor) to ∼24th mag in ugriz. The primary goals of SMASH are
to identify low surface brightness stellar populations associated with
the stellar halos and tidal debris of the Clouds, and to derive spatially
resolved star formation histories. Here, we present a summary of the
survey, its data reduction, and a description of the first public Data
Release (DR1). The SMASH DECam data have been reduced with a combination
of the NOAO Community Pipeline, the PHOTRED automated point-spread-function
photometry pipeline, and custom calibration software. The astrometric
precision is ∼15 mas and the accuracy is ∼2 mas with respect to the
Gaia reference frame. The photometric precision is ∼0.5%-0.7% in griz
and ∼1% in u with a calibration accuracy of ∼1.3% in all bands. The
median 5σ point source depths in ugriz are 23.9, 24.8, 24.5, 24.2,
and 23.5 mag. The SMASH data have already been used to discover the
Hydra II Milky Way satellite, the SMASH 1 old globular cluster likely
associated with the LMC, and extended stellar populations around the
LMC out to R∼18.4 kpc. SMASH DR1 contains measurements of ∼100 million
objects distributed in 61 fields. A prototype version of the NOAO Data
Lab provides data access and exploration tools.
Description:
The DECam imager is composed of 62 chips (59 and a half were functional
throughout most of the SMASH observing; CCDNUM 2, 61, and one amplifier
of 31 were not producing useful science data, although CCDNUM 2
started working again as of 2016 December 29) from Lawrence Berkeley
National Lab (LBNL) arranged in a hexagonal pattern covering a field
of view of ∼3 deg2 and a width of ∼2°. The SMASH fields were
chosen using an all-sky tiling scheme in which we laid down a uniform
hex pattern of field centers with 1.7° separation between field
centers with coordinates based on an Interrupted Mollweide projection.
Objects:
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RA (ICRS) DE Designation(s)
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05 23 34.6 -69 45 22 Large Magellanic Cloud = NAME LMC
00 52 38.0 -72 48 01 Small Magellanic Cloud = NAME SMC
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 89 248 SMASH Fields Table
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See also:
II/351 : VISTA Magellanic Survey (VMC) catalog (Cioni+, 2011)
J/ApJ/562/303 : Old Stellar Populations of the SMC (Dolphin+ 2001)
J/AJ/138/1243 : The star formation history of the LMC (Harris+, 2009)
J/MNRAS/449/639 : VMC survey. XIV. SFR in SMC (Rubele+, 2015)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Num [1/248] Field number
5- 13 A9 --- Name Field name
15- 16 I2 h RAh Hour of Right Ascension (J2000)
18- 19 I2 min RAm Minute of Right Ascension (J2000)
21- 25 F5.2 s RAs Second of Right Ascension (J2000)
27 A1 --- DE- Sign of the Declination (J2000)
28- 29 I2 deg DEd Degree of Declination (J2000)
31- 32 I2 arcmin DEm Arcminute of Declination (J2000)
34- 38 F5.2 arcsec DEs Arcsecond of Declination (J2000)
40- 48 F9.5 deg RAdeg Right Ascension in decimal degrees (J2000)
50- 59 F10.6 deg DEdeg Declination in decimal degrees (J2000)
61- 69 F9.5 deg MSLON Magellanic Stream longitude (1)
71- 79 F9.5 deg MSLAT Magellanic Stream latitude (1)
81 I1 --- uZPCal [0/4]? u-band zero-point calibration type (2)
83 I1 --- gZPCal [1/4]? g-band zero-point calibration type (2)
85 I1 --- rZPCal [1/4]? r-band zero-point calibration type (2)
87 I1 --- iZPCal [1/4]? i-band zero-point calibration type (2)
89 I1 --- zZPCal [1/4]? z-band zero-point calibration type (2)
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Note (1): The Magellanic Stream coordinate system is defined in Nidever et al.
(2008ApJ...679..432N 2008ApJ...679..432N).
Note (2): Calibration type as follows:
1 = Photometric DECam data;
2 = Overlap with photometric DECam data;
3 = 0.9 m calibration data;
4 = SMASH-Gaia color-color relations.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 01-Aug-2018