J/MNRAS/460/30 gi photometry of Sextans dSph galaxy stars (Roderick+, 2016)
Structural analysis of the Sextans dwarf spheroidal galaxy.
Roderick T.A., Jerjen H., Da Costa G.S., Mackey A.D.
<Mon. Not. R. Astron. Soc., 460, 30-43 (2016)>
=2016MNRAS.460...30R 2016MNRAS.460...30R (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Photometry, SDSS
Keywords: galaxies: dwarf - galaxies: evolution -
galaxies: fundamental parameters - galaxies: individual: Sextans
Abstract:
We present wide-field g- and i-band stellar photometry of the Sextans
dwarf spheroidal galaxy and its surrounding area out to four times its
half-light radius (rh=695pc), based on images obtained with the Dark
Energy Camera at the 4-m Blanco telescope at CTIO. We find clear
evidence of stellar substructure associated with the galaxy, extending
to a distance of 82-arcmin (2kpc) from its centre. We perform a
statistical analysis of the overdensities and find three distinct
features, as well as an extended halo-like structure, to be
significant at the 99.7 per cent confidence level or higher. Unlike
the extremely elongated and extended substructures surrounding the
Hercules dwarf spheroidal galaxy, the overdensities seen around
Sextans are distributed evenly about its centre, and do not appear to
form noticeable tidal tails. Fitting a King model to the radial
distribution of Sextans stars yields a tidal radius
rt=83.2-arcmin±7.1 arcmin (2.08±0.18kpc), which implies the
majority of detected substructure is gravitationally bound to the
galaxy. This finding suggests that Sextans is not undergoing
significant tidal disruption from the Milky Way, supporting the
scenario in which the orbit of Sextans has a low eccentricity.
Description:
Observations were conducted on 2013 February 15 using DECam at the
CTIO 4-m Blanco telescope, as part of observing proposal 2013A-0617
(PI: D. Mackey). The total DECam field-of-view is 3 deg2, formed by a
hexagonal mosaic of 62 2Kx4K CCDs, each with a pixel scale of
0.27arcsec/pixel.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fig13.dat 100 6191 Catalogue of all stars corresponding to the
spatial distribution of overdensities in Fig. 13
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See also:
J/A+A/566/A44 : gr photometry of Sextans A and Sextans B (Bellazzini+, 2014)
Byte-by-byte Description of file: fig13.dat
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Bytes Format Units Label Explanations
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1- 24 E24.19 deg RAdeg Right ascension (J2000)
26- 50 E25.19 deg DEdeg Declination
52- 75 E24.19 mag gmag g magnitude
77-100 E24.19 mag imag i magnitude
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 29-Sep-2017