J/A+A/562/A73 ZJ VISTA photometry in NGC253 stellar halo (Greggio+, 2014)
A panoramic VISTA of the stellar halo of NGC 253.
Greggio L., Rejkuba M., Gonzales O.A., Arnaboldi M., Iodice E., Irwin M.,
Neeser M.J., Emerson J.
<Astron. Astrophys. 562, A73 (2014)>
=2014A&A...562A..73G 2014A&A...562A..73G
ADC_Keywords: Galaxies, nearby ; Stars, late-type ; Photometry, infrared
Keywords: galaxies: stellar content - galaxies: structure - galaxies: halos -
galaxies: formation - galaxies: individual: NGC 253
Abstract:
We use images obtained with the VISTA telescope in the Z and J bands
to analyze the stellar content of NGC 253, a nearly edge on spiral
galaxy in the Sculptor group. The very deep photometry, down to
J∼23.5, and the wide area covered allow us to trace the red giant
branch and asymptotic giant branch (AGB) stars that belong to the
outer disk and the halo of NGC 253, out to 50kpc along the galaxy
minor axis.
We confirm the existence of an extraplanar component, with a prominent
southern shelf and detect for the first time a symmetrical feature on
the north side. The star counts profile along the major axis show a
clear break at 25kpc from the center, signalling the transition from
the disk to the halo. The isodensity contours show a flat inner halo
that blends with a more extended, diffuse, rounder outer halo. In such
external structure, we detect an overdensity at about 28kpc from the
plane and extending over 20kpc parallel with the disk of the galaxy.
The spatially resolved color magnitude diagrams show a rather
homogeneous stellar population across the tile. Particularly
surprising is the presence of bright, intermediate age, AGB stars
found scattered over a large volume.
Description:
This catalogue lists position, magnitude and photometric error of
stellar sources identified on the VISTA Z and J images of the NGC 253
spiral galaxy. The data were analyzed with the VISTA data flow system
at the Cambridge University Astronomy Survey Unit, and photometry
carried out with the imcore package, which provides a morphological
classification for each detection. The catalogue presented here is
referred to as Catalogue B in the paper, and includes sources
classified as stellar or likely stellar in both filter (Type=1), plus
sources classified as stellar on the J and extended on the Z tile
(Type=4). The last column of the catalogue reports this
classification.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalogb.dat 124 82712 Positions, magnitudes, photometric errors,
types for each source
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See also:
J/MNRAS/388/849 : NGC253 XMM observations (Barnard+, 2008)
J/ApJ/736/24 : VI photometry of sources in NGC253 halo (Bailin+, 2011)
J/A+A/550/A12 : NGC253 near-infrared H2 emission (Rosenberg+, 2013)
Byte-by-byte Description of file: catalogb.dat
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Bytes Format Units Label Explanations
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4 I1 h RAh Right ascension (J2000)
7- 8 I2 min RAm Right ascension (J2000)
11- 16 F6.3 s RAs Right ascension (J2000)
19 A1 --- DE- Declination sign (J2000)
20- 21 I2 deg DEd Declination (J2000)
24- 25 I2 arcmin DEm Declination (J2000)
28- 32 F5.2 arcsec DEs Declination (J2000)
35- 43 F9.3 pix Jx X-position in pixels on the J tile
46- 54 F9.3 pix Jy Y-position in pixels on the J tile
59- 65 F7.4 mag Jmag Magnitude on the J tile
71- 76 F6.4 mag e_Jmag Error on J magnitude
79- 87 F9.3 pix Zx X-position in pixels on the Z tile
90- 98 F9.3 pix Zy Y-position in pixels on the J tile
103-109 F7.4 mag Zmag Magnitude on the Z tile
115-120 F6.4 mag e_Zmag Error on Z magnitude
124 I1 --- Type [1/4] Note (1)
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Note (1): Type as follows:
1 = object classified as stellar or stellar like on both Z and J tiles
4 = object classified as stellar on the J tile and extended on the Z tile
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Acknowledgements:
Laura Greggio, laura.greggio(at)oapd.inaf.it
References:
(End) Patricia Vannier [CDS] 07-Feb-2014