J/ApJ/920/63 Metallicity for 317 RGB-stars in NGC 147 (Zhuang+, 2021)
NGC 147 Corroborates the Break in the Stellar Mass-Stellar Metallicity Relation
for Galaxies.
Zhuang Z.,Kirby E.N.,Leethochawalit N.,de los Reyes M.A.C.
<Astrophys. J., 920, 63 (2021)>
=2021ApJ...920...63Z 2021ApJ...920...63Z
ADC_Keywords: Galaxies; Stars, giant; Photometry, VRI; Abundances, [Fe/H];
Effective temperatures
Keywords: Local Group ; Galaxy abundances ; Metallicity ; Chemical
abundances ; Stellar abundances ; Dwarf elliptical galaxies
Abstract:
The stellar mass-stellar metallicity relation (MZR) is an essential
approach to probing the chemical evolution of galaxies. It reflects
the balance between galactic feedback and gravitational potential as a
function of stellar mass. However, the current MZR of local dwarf
satellite galaxies (M*≲108M☉; measured from resolved stellar
spectroscopy) may not be reconcilable with that of more massive
galaxies (M*>109.5M☉; measured from integrated-light
spectroscopy). Such a discrepancy may result from a systematic
difference between the two methods, or it may indicate a break in the
MZR around 109M☉. To address this question, we measured the
stellar metallicity of NGC147 from integrated light using the Palomar
Cosmic Web Imager. We compared the stellar metallicity estimates from
integrated light with measurements from resolved stellar spectroscopy
and found them to be consistent within 0.1dex. On the other hand, the
high-mass MZR overpredicts the metallicity by 0.6dex at the mass of
NGC147. Therefore, our results tentatively suggest that the
discrepancy between the low-mass MZR and high-mass MZR should not be
attributed to a systematic difference in techniques. Instead, real
physical processes cause the transition in the MZR. In addition, we
discovered a positive age gradient in the innermost region and a
negative metallicity gradient from the resolved stars at larger radii,
suggesting a possible outside-in formation of NGC147.
Description:
We used archival Keck/DEIMOS observations of four slitmasks along the
major axis of NGC 147.
Objects:
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RA (2000) DE Designation(s)
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00 33 12.12 +48 30 31.4 NGC 147 = 2MASX J00331212+4830314
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 92 317 Metallicity catalog for RGB stars observed with
Keck/DEIMOS
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See also:
J/AJ/131/332 : Velocities of individual stars in NGC 205 (Geha+, 2006)
J/A+A/459/85 : O/H and gas densities in star-forming galaxies (Nagao+, 2006)
J/MNRAS/371/703 : MILES library of empirical spectra (Sanchez-Blazquez+, 2006)
J/ApJ/682/1217 : Abundances in red giants in 7 globular clusters (Kirby+, 2008)
J/ApJ/705/328 : Abundance measurements in Sculptor dSph (Kirby+, 2009)
J/ApJS/182/216 : Surface photometry of Virgo ellipticals (Kormendy+, 2009)
J/ApJ/711/361 : Local Group dE galaxies. II. (Geha+, 2010)
J/ApJS/191/352 : Abundances in stars Milky Way dwarf satellites (Kirby+, 2010)
J/MNRAS/413/813 : ATLAS3D project. I. (Cappellari+, 2011)
J/ApJ/758/11 : Bayesian distances to M31 satellites (Conn+, 2012)
J/ApJ/765/140 : Stacked spectra of SDSS star forming galaxies (Andrews+, 2013)
J/ApJ/779/102 : Metallicities of RGB stars in dwarf galaxies (Kirby+, 2013)
J/ApJ/776/80 : PAndAS view of Andromeda satellites. I. (Martin+, 2013)
J/ApJ/790/73 : Fe & alpha abundance of RGBs in M31 satellites (Vargas+, 2014)
J/ApJ/789/147 : Star formation histories of LG dwarf galaxies (Weisz+, 2014)
J/ApJ/834/9 : Spectroscopy obs. of LeoA, Aqr & Sgr dwarf gal. (Kirby+, 2017)
J/ApJ/856/15 : Stellar mass-metallicity relation. I. (Leethochawalit+, 2018)
J/ApJ/885/100 : Star mass-metallicity relation. II. (Leethochawalit+, 2019)
J/AJ/159/46 : Elemental abundances 416 stars 5 dSphs of M31 (Kirby+, 2020)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- Name Identifier of star
7- 8 I2 h RAh [0] Hour of Right Ascension (J2000)
10- 11 I2 min RAm [32/34] Minute of Right Ascension (J2000)
13- 16 F4.1 s RAs Second of Right Ascension (J2000)
18 A1 --- DE- [+] Sign of the Declination (J2000)
19- 20 I2 deg DEd [48] Degree of Declination (J2000)
22- 23 I2 arcmin DEm [16/43] Arcminute of Declination (J2000)
25- 28 F4.1 arcsec DEs Arcsecond of Declination (J2000)
30 A1 --- Filt1 [g]? First filter
32- 37 F6.3 mag mag1 [21.8/24.3]? Extinction-corrected mag Filt1 (1)
39- 43 F5.3 mag e_mag1 [0.01/0.2]? Uncertainty in mag1
45 A1 --- Filt2 [i]? Second filter
47- 52 F6.3 mag mag2 [20.3/22.1]? Extinction-corrected mag Filt2 (1)
54- 58 F5.3 mag e_mag2 [0.008/0.05]? Uncertainty in mag2
60- 63 I4 K Teff [3500/4959] Effective temperature
65- 66 I2 K e_Teff [0/89] Uncertainty in Teff
68- 71 F4.2 [cm/s2] logg [0/1.23] Log of surface gravity
73- 76 F4.2 [cm/s2] e_logg [0.1] Uncertainty in logg
78- 81 F4.2 km/s vt [1.85/2.14] Microturbulent velocity
83- 87 F5.2 [Sun] [Fe/H] [-3.35/-0.02] Iron abundance relative to the Sun
89- 92 F4.2 [Sun] e_[Fe/H] [0.1/0.5] Uncertainty in [Fe/H]
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Note (1): PAndAS photometry corrected for extinction.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 10-Feb-2023