J/MNRAS/448/1314 Line list for seven target PAndAS clusters (Sakari+, 2015)
Integrated light chemical tagging analyses of seven M31 outer halo globular
clusters from the Pan-Andromeda Archaeological Survey.
Sakari C.M., Venn K.A., Mackey D., Shetrone M.D., Dotter A.,
Ferguson A.M.N., Huxor A.
<Mon. Not. R. Astron. Soc., 448, 1314-1334 (2015)>
=2015MNRAS.448.1314S 2015MNRAS.448.1314S (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Clusters, globular ; Magnitudes ;
Abundances, [Fe/H] ; Spectroscopy ; Equivalent widths
Keywords: globular clusters: general - galaxies: abundances -
galaxies: evolution - galaxies: individual: M31 -
galaxies: star clusters: general
Abstract:
Detailed chemical abundances are presented for seven M31 outer halo
globular clusters (with projected distances from M31 greater than 30 kpc),
as derived from high-resolution integrated light spectra taken with
the Hobby-Eberly Telescope. Five of these clusters were recently
discovered in the Pan-Andromeda Archaeological Survey (PAndAS) - this
paper presents the first determinations of integrated Fe, Na, Mg, Ca,
Ti, Ni, Ba, and Eu abundances for these clusters. Four of the target
clusters (PA06, PA53, PA54, and PA56) are metal poor ([Fe/H]< -1.5),
α-enhanced (though they are possibly less α-enhanced than
Milky Way stars at the 1σ level), and show signs of star-to-star
Na and Mg variations. The other three globular clusters (H10, H23, and
PA17) are more metal rich, with metallicities ranging from [Fe/H]=-1.4
to -0.9. While H23 is chemically similar to Milky Way field stars,
Milky Way globular clusters, and other M31 clusters, H10 and PA17,
have moderately low [Ca/Fe], compared to Milky Way field stars and
clusters. Additionally, PA17's high [Mg/Ca] and [Ba/Eu] ratios are
distinct from Milky Way stars, and are in better agreement with the
stars and clusters in the Large Magellanic Cloud. None of the clusters
studied here can be conclusively linked to any of the identified
streams from PAndAS; however, based on their locations, kinematics,
metallicities, and detailed abundances, the most metal-rich PAndAS
clusters H23 and PA17 may be associated with the progenitor of the
Giant Stellar Stream, H10 may be associated with the SW cloud, and
PA53 and PA56 may be associated with the eastern cloud.
Description:
The targets were observed with the Hobby-Eberly Telescope (HET;
Ramsey et al. 1998, Proc. SPIE, 3352, 34; Shetrone et al.
2007PASP..119..556S 2007PASP..119..556S) at McDonald Observatory in Fort Davis, TX in 2011
and early 2012. The High Resolution Spectrograph (HRS; Tull 1998,
Proc. SPIE, 3355, 387) was utilized with the 3-arcsec fibre and a slit
width of 1 arcsec, yielding an instrumental spectral resolution of R=30000.
With the 600 g/mm cross-disperser set to a central wavelength of 6302.9Å,
wavelength coverages of ∼5320-6290 and ∼6360-7340Å were achieved in
the blue and the red, respectively. The 3-arcsec fibre provided coverage
of the clusters past their half-light radii; the additional sky fibres
(located 10 arcsec from the central object fibre) provided simultaneous
observations for sky subtraction. Exposure times were calculated to
obtain a total signal-to-noise ratio (S/N)=80 (per resolution element),
although not all targets received sufficient time to meet this goal.
Objects:
----------------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------------
00 42 44.33 +41 16 07.5 M31 = NAME Andromeda
----------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 61 7 Properties of the target PAndAS clusters
table3.dat 67 129 The Line List
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See also:
V/143 : Revised Bologna Catalog of M31 clusters, V.5 (Galleti+ 2012)
J/AJ/122/2458 : M31 globular clusters from HST (Barmby+, 2001)
J/AJ/124/234 : M31 outer halo UBVRI photometry and metallicity
(Reitzel+, 2002)
J/AJ/133/2764 : M31 globular clusters structural parameters (Barmby+, 2007)
J/A+A/508/1285 : Metallicity estimates of M31 globular clusters
(Galleti+, 2009)
J/A+A/544/A155 : HST photometry of M31 globular clusters (Federici+, 2012)
J/A+A/549/A60 : Ages and [Fe/H] of M31 globular clusters (Cezario+, 2013)
J/ApJ/769/10 : Spectroscopy of M31 globular clusters (Jacoby+, 2013)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Name PAndAS cluster name
6- 7 I2 h RAh Hour of Right Ascension (J2000)
9- 10 I2 min RAm Minute of Right Ascension (J2000)
12- 15 F4.1 s RAs Second of Right Ascension (J2000)
17 A1 --- DE- Sign of the 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- 32 F4.1 mag Vint Integrated V-band magnitude
34- 38 F5.1 kpc Rproj Projected distance from the centre of M31
40- 44 A5 [-] [Fe/H] Photometric metallicity estimate (1)
45 A1 --- n_[Fe/H] [c] Note on [Fe/H] (2)
47- 55 A9 --- Assoc Spatial association with stream? (N=No)
57- 61 A5 --- Ref Reference(s) (3)
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Note (1): Used to constrain the parameters of the input isochrones; see
Section 3. [Fe/H] estimates are based on Galactic GC fiducial fits.
"MP" indicates a metal-poor cluster ([Fe/H]~< -1.5); fiducial fits
will be given in Mackey et al. (2016MNRAS.460L.114M 2016MNRAS.460L.114M).
Note (2): Note as follows:
c = PA17 does not have an HST CMD, and there is therefore no a priori
information about its metallicity or horizontal branch (HB) morphology.
Note (3): Reference as follows:
1 = Mackey et al. (2007ApJ...655L..85M 2007ApJ...655L..85M);
2 = Veljanoski et al. (2014MNRAS.442.2929V 2014MNRAS.442.2929V);
3 = Huxor et al. (2014MNRAS.442.2165H 2014MNRAS.442.2165H);
4 = Mackey et al. (2016MNRAS.460L.114M 2016MNRAS.460L.114M).
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 8 F8.3 0.1nm lambda Spectral line wavelength (Å)
10- 13 A4 --- El Element and ionization state
15- 19 F5.3 eV EP Excitation Potential
21- 26 F6.3 [-] loggf Oscillator strength
28- 32 F5.1 0.1pm EW-H10 ?=- H10 equivalent width (mÅ)
33 A1 --- n_EW-H10 [s] Mote on EW-H10 (1)
34- 38 F5.1 0.1pm EW-H23 ?=- H23 equivalent width (mÅ)
39 A1 --- n_EW-H23 [s] Mote on EW-H23 (1)
40- 44 F5.1 0.1pm EW-PA06 ?=- PA06 equivalent width (mÅ)
45 A1 --- n_EW-PA06 [s] Mote on EW-PA06 (1)
46- 50 F5.1 0.1pm EW-PA17 ?=- PA17 equivalent width (mÅ)
51 A1 --- n_EW-PA17 [s] Mote on EW-PA17 (1)
52- 56 F5.1 0.1pm EW-PA53 ?=- PA53 equivalent width (mÅ)
57 A1 --- n_EW-PA53 [s] Mote on EW-PA53 (1)
58- 61 F4.1 0.1pm EW-PA54 ?=- PA54 equivalent width (mÅ)
62 A1 --- n_EW-PA54 [s] Mote on EW-PA54 (1)
63- 67 F5.1 0.1pm EW-PA56 ?=- PA56 equivalent width (mÅ)
68 A1 --- n_EW-PA56 [s] Mote on EW-PA56 (1)
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Note (1): s indicates that the lines were measured with spectrum syntheses.
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History:
From electronic version of the journal
(End) Tiphaine Pouvreau [CDS] 21-Nov-2017