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J/ApJ/788/77  Milky Way L/T/M-dwarfs identified in BoRG survey (Holwerda+, 2014)

Milky Way red dwarfs in the BoRG survey: galactic scale-height and the distribution of dwarf stars in WFC3 imaging. Holwerda B.W., Trenti M., Clarkson W., Sahu K., Bradley L., Stiavelli M., Pirzkal N., De Marchi G., Andersen M., Bouwens R., Ryan R. <Astrophys. J., 788, 77 (2014)> =2014ApJ...788...77H (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Stars, dwarfs ; Photometry, HST ; Photometry, infrared ; Stars, distances Keywords: Galaxy: disk - Galaxy: fundamental parameters - Galaxy: halo - Galaxy: structure - stars: low-mass Abstract: We present a tally of Milky Way late-type dwarf stars in 68 Wide Field Camera 3 (WFC3) pure-parallel fields (227 arcmin2) from the Brightest of Reionizing Galaxies survey for high-redshift galaxies. Using spectroscopically identified M-dwarfs in two public surveys, the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey and the Early Release Science mosaics, we identify a morphological selection criterion using the half-light radius (r50), a near-infrared J-H, G-J color region where M-dwarfs are found, and a V-J relation with M-dwarf subtype. We apply this morphological selection of stellar objects, color-color selection of M-dwarfs, and optical-near-infrared color subtyping to compile a catalog of 274 M-dwarfs belonging to the disk of the Milky Way with a limiting magnitude of mF125W<24(AB). Based on the M-dwarf statistics, we conclude that (1) the previously identified north-south discrepancy in M-dwarf numbers persists in our sample; there are more M-dwarfs in the northern fields on average than in southern ones, (2) the Milky Way's single disk scale-height for M-dwarfs is 0.3-4 kpc, depending on subtype, (3) the scale-height depends on M-dwarf subtype with early types (M0-4) high scale-height (z0=3-4 kpc) and later types M5 and above in the thin disk (z0=0.3-0.5 kpc), (4) a second component is visible in the vertical distribution, with a different, much higher scale-height in the southern fields compared to the northern ones. We report the M-dwarf component of the Sagittarius stream in one of our fields with 11 confirmed M-dwarfs, seven of which are at the stream's distance. In addition to the M-dwarf catalog, we report the discovery of 1 T-dwarfs and 30 L-dwarfs from their near-infrared colors. The dwarf scale-height and the relative low incidence in our fields of L- and T-dwarfs in these fields makes it unlikely that these stars will be interlopers in great numbers in color-selected samples of high-redshift galaxies. The relative ubiquity of M-dwarfs however will make them ideal tracers of Galactic halo substructure with EUCLID and reference stars for James Webb Space Telescope observations. Description: Our principal data set is the WFC3 data from the BoRG (HST GO/PAR-11700; Trenti et al. 2011ApJ...727L..39T; Bradley et al. 2012ApJ...760..108B) survey to identify Milky Way dwarf stars from their morphology and color. The BoRG observations are undithered HST/WFC3 conducted in pure-parallel with the telescope pointing to a primary spectroscopic target with the Cosmic Origin Spectrograph (COS; typically a high-z QSO at high Galactic latitude). The limitations for such observations are primarily that no dithering strategy can be used (final images are at WFC3 native pixel scale) and total exposure times are dictated by the primary program. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table4.dat 67 24 The M-dwarfs Identified by PEARS in the CANDELS Field table5.dat 67 22 The M-dwarfs Identified by PEARS in the ERS Mosaic table14.dat 137 30 The 30 L-dwarfs Identified in BoRG table15.dat 137 1 The 1 T-dwarfs Identified in BoRG table16.dat 137 274 The 274 M-dwarfs identified in BoRG
See also: B/hst : HST Archived Exposures Catalog (STScI, 2007) J/AJ/123/3409 : SDSS M, L, and T dwarfs (Hawley+, 2002) J/A+A/441/653 : 32 DENIS nearby red dwarfs (Crifo+, 2005) Byte-by-byte Description of file: table4.dat table5.dat
Bytes Format Units Label Explanations
1- 6 I6 --- ID Identification number, NNNNNN, [PBM2009] sNNNNNN in Simbad 8- 10 F3.1 --- SpType Sub M spectral type 12- 20 F9.6 deg RAdeg Rigth ascension (J2000) 22- 31 F10.6 deg DEdeg Declination (J2000) 33- 37 F5.2 mag F435Wmag F435W magnitude (1) 39- 43 F5.2 mag F606Wmag F606W magnitude (1) 45- 49 F5.2 mag F775Wmag F775W magnitude (1) 51- 55 F5.2 mag F850Wmag F850W magnitude (1) 57- 61 F5.2 mag F125Wmag F125W magnitude (2) 63- 67 F5.2 mag F160Wmag F160W magnitude (2)
Note (1): Optical magnitudes are from Pirzkal et al. (2009, Cat. J/ApJ/695/1591) Note (2): F125W and F160W magnitudes from our sextractor catalog of the CANDELS field (table 4) or ERS mosaic (table 5).
Byte-by-byte Description of file: table14.dat table15.dat table16.dat
Bytes Format Units Label Explanations
1- 5 A5 --- --- [borg_] 6- 21 A16 --- borg Source identifier (borg_HHMM+DDMM.NNNN.N) 23- 32 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000) 34- 43 F10.6 deg DEdeg Declination in decimal degrees (J2000) 45- 54 F10.6 deg GLON Galactic longitude 56- 65 F10.6 deg GLAT Galactic latitude 67- 70 F4.1 mag F098Mmag HST/WFC3 F098M filter magnitude 72- 74 F3.1 mag e_F098Mmag Uncertainty in F098Mmag 76- 79 F4.1 mag F125Wmag HST/WFC3 F125W filter magnitude 81- 83 F3.1 mag e_F125Wmag Uncertainty in F125Wmag 85- 88 F4.1 mag F160Wmag HST/WFC3 F160W filter magnitude 90- 92 F3.1 mag e_F160Wmag Uncertainty in F160Wmag 94- 97 F4.1 mag F606Wmag HST/WFC3 F606W filter magnitude 99-102 F4.1 mag e_F606Wmag Uncertainty in F606Wmag 104-107 F4.1 --- Mtype ? M-dwarf type; see Equ. 4. 109-111 F3.1 --- e_Mtype ? Uncertainty in Mtype 113-117 F5.2 mag DM ? Distance modulus 119-123 F5.2 kpc Dist ? Distance 125-130 F6.2 kpc Z ? Milky Way scale height 132-137 F6.2 kpc Rad []? Galactic radius
History: From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 07-Jul-2017
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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