J/ApJ/805/189 Highly likely members of the Sgr stream (Hyde+, 2015)
Selecting Sagittarius: identification and chemical characterization of the
Sagittarius stream.
Hyde E.A., Keller S., Zucker D.B., Ibata R., Siebert A., Lewis G.F.,
Penarrubia J., Irwin M., Gilmore G., Lane R.R., Koch A., Conn A.R.,
Diakogiannis F.I., Martell S.
<Astrophys. J., 805, 189 (2015)>
=2015ApJ...805..189H 2015ApJ...805..189H (SIMBAD/NED BibCode)
ADC_Keywords: Abundances ; Stars, halo
Keywords: galaxies: dwarf; Galaxy: formation; Galaxy: halo;
Galaxy: kinematics and dynamics
Abstract:
Wrapping around the Milky Way, the Sagittarius stream is the dominant
substructure in the halo. Our statistical selection method has allowed
us to identify 106 highly likely members of the Sagittarius stream.
Spectroscopic analysis of metallicity and kinematics of all members
provides us with a new mapping of the Sagittarius stream. We find
correspondence between the velocity distribution of stream stars and
those computed for a triaxial model of the Milky Way dark matter halo.
The Sagittarius trailing arm exhibits a metallicity gradient, ranging
from -0.59 to -0.97dex over 142°. This is consistent with the
scenario of tidal disruption from a progenitor dwarf galaxy that
possessed an internal metallicity gradient. We note high metallicity
dispersion in the leading arm, causing a lack of detectable gradient
and possibly indicating orbital phase mixing. We additionally report
on a potential detection of the Sextans dwarf spheroidal in our data.
Description:
Once selected, candidates were subsequently targeted with the AAOmega
fiber-fed multi-object spectrograph on the 3.9m Anglo-Australian
Telescope (AAT; R=8000 and 10000 in the blue and red respectively;
the wavelength range is 4250-6000Å in the blue and 8450-9000Å
in the red). The data for both the stream and core observing programs
were obtained on several observing runs spanning 2009-2011.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 64 106 The selected 106 likely Sagittarius Stream
members with modified RAVE pipeline metallicity,
surface gravity, and effective temperature values
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See also:
III/272 : RAVE 4th data release (Kordopatis+, 2013)
III/265 : RAVE 3rd data release (Siebert+, 2011)
I/317 : The PPMXL Catalog (Roeser+ 2010)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
J/AJ/145/163 : Catalog of stars in Sgr dwarf galaxy (Newby+, 2013)
J/ApJ/751/130 : SDSS-DR7 red HB stars spectroscopic data (Shi+, 2012)
J/ApJ/731/119 : BHB candidates in Sagittarius stream (Ruhland+, 2011)
J/ApJ/708/1290 : A 2MASS view of the Sgr dSph. VI. (Chou+, 2010)
J/PASP/121/1180 : Color panorama image of the Milky Way (Mellinger+, 2009)
J/ApJ/670/346 : M giant stars in the Sgr dwarf galaxy. V. (Chou+, 2007)
J/A+A/464/201 : RGB stars in Sagittarius streams (Monaco+, 2007)
J/AJ/128/245 : M giant stars in the Sgr dwarf galaxy (Majewski+, 2004)
J/AJ/127/2031 : Catalog of neighboring galaxies (Karachentsev+, 2004)
J/A+A/414/503 : Abundances in the Sgr dSph (Bonifacio+, 2004)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/106] Running sequence number
5- 6 I2 h RAh Hour of right ascension (J2000)
8- 9 I2 min RAm Minute of right ascension (J2000)
11- 15 F5.2 s RAs Second of right ascension (J2000)
17 A1 --- DE- Sign of declination (J2000)
18- 19 I2 deg DEd Degree of declination (J2000)
21- 22 I2 arcmin DEm Arcminute of declination (J2000)
24- 27 F4.1 arcsec DEs Arcsecond of declination (J2000)
29- 34 F6.2 deg lambda [13.5/332.4] Sgr coordinate system Λ (1)
36- 40 F5.2 deg B [-8.5/28] Sgr coordinate system B (1)
42- 45 F4.2 [cm/s2] logg [0.2/2.3] Log gravity
47- 52 F6.1 K Teff [3509/4891] Effective temperature
54- 58 F5.2 [Sun] [M/H] [-1.8/0.5] Metallicity [m/H]
60- 64 F5.2 --- Rcoef [15.3/52.7] RAVE correlation coefficient (2)
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Note (1): For coordinates, we adopt the Sgr coordinate system Λ, B as
defined by Majewski et al. (2003ApJ...599.1082M 2003ApJ...599.1082M). This system is
oriented such that the equator is defined by the Sgr stream midplane,
with the origin of Λ centered on the Sgr core.
Note (2): The RAVE correlation coefficient (Rcoef) determines the goodness of
the fit between the star spectrum and the corresponding template
through a standard cross correlation procedure (Tonry & Davis
1979AJ.....84.1511T 1979AJ.....84.1511T). Higher values of Rcoef indicate a better fit.
See section 4 for further explanations.
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 18-Sep-2015