J/ApJ/882/9 SFR & gas-phase metallicity in MaNGA gal. (Sanchez-Menguiano+, 2019)
Characterizing the local relation between star formation rate and gas-phase
metallicity in MaNGA spiral galaxies.
Sanchez-Menguiano L., Sanchez Almeida J., Munoz-Tunon C., Sanchez S.F.,
Filho M., Hwang H.-C., Drory N.
<Astrophys. J., 882, 9 (2019)>
=2019ApJ...882....9S 2019ApJ...882....9S
ADC_Keywords: Abundances; Galaxies, spectra; Velocity dispersion; Morphology;
Surveys
Keywords: galaxies: abundances ; galaxies: evolution ; galaxies: formation ;
galaxies: star formation
Abstract:
The role of gas accretion in galaxy evolution is still a matter of
debate. The presence of inflows of metal-poor gas that trigger star
formation bursts of low metallicity has been proposed as an
explanation for the local anticorrelation between star formation rate
(SFR) and gas-phase metallicity (Zg) found in the literature. In the
present study, we show how the anticorrelation is also present as part
of a diversified range of behaviors for a sample of more than
700 nearby spiral galaxies from the SDSS-IV MaNGA survey. We have
characterized the local relation between SFR and Zg after
subtracting the azimuthally averaged radial profiles of both
quantities. Of the analyzed galaxies, 60% display an SFR-Zg
anticorrelation, with the remaining 40% showing no correlation (19%)
or positive correlation (21%). Applying a random forest
machine-learning algorithm, we find that the slope of the correlation
is mainly determined by the average gas-phase metallicity of the
galaxy. Galaxy mass, g-r colors, stellar age, and mass density seem to
play a less significant role. This result is supported by the
performed second-order polynomial regression analysis. Thus, the local
SFR-Zg slope varies with the average metallicity, with the more
metal-poor galaxies presenting the lowest slopes (i.e., the strongest
SFR-Zg anticorrelations), and reversing the relation for more
metal-rich systems. Our results suggest that external gas accretion
fuels star formation in metal-poor galaxies, whereas in metal-rich
systems, the gas comes from previous star formation episodes.
Description:
Mapping Nearby Galaxies at Apache Point Observatory (MaNGA; Bundy+
2015ApJ...798....7B 2015ApJ...798....7B) is an ongoing survey developed as part of the
SDSS-IV project.
The observations are conducted on the basis of an integral field unit
(IFU) fiber system feeding the BOSS spectrographs on the Sloan 2.5m
telescope at Apache Point Observatory, New Mexico. The field of view
(FoV) of the instrument varies from 12.5" to 32.5" in diameter. The
spectrographs provide wavelength coverage from 3600 to 10300Å, with
a nominal resolution of R∼2100 at 6000Å.
In this study, the analyzed sample is extracted from the internal
release MaNGA Product Launches 7 (MPL-7) comprising 4688 galaxies.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 88 736 Galaxy properties and derived slopes for
the local SFR-Zg relation
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See also:
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
J/ApJ/695/259 : Massive metal-poor galaxies from SDSS (Peeples+, 2009)
J/MNRAS/414/2602 : Automated classification of HIP variables (Dubath+, 2011)
J/A+A/559/A114 : Updated O3N2 and N2 abundance indicators (Marino+, 2013)
J/A+A/587/A70 : CALIFA face-on spiral galaxies (Sanchez-Menguiano+, 2016)
J/AJ/154/86 : MaNGA catalog, DR15 (Wake+, 2017)
J/MNRAS/466/2570 : Low ionization emission-line regions (Belfiore+, 2017)
J/A+A/623/A122 : Sample of MaNGA galaxies properties (Pilyugin+, 2019)
J/A+A/623/A171 : Mkn 848 MaNGA 3-D data cube (Perna+, 2019)
http://www.sdss.org/ : SDSS home page
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- MaNGA Galaxy identifier defined as the
[plate]-[ifudesign] of the MaNGA
observations (Wake+, 2017, J/AJ/154/86)
13- 16 F4.2 [-] Abund [8.17/8.7]? Gas-phase oxygen abundance
([12+log(O/H)]) value at disk effective
radius
18- 22 F5.2 [Msun] Mass [7.7/11.3] Galaxy mass
24- 28 F5.2 mag g-r [-1.1/1.6] g-r color index
30- 33 F4.2 [yr] LW-age [7.3/10]? Average LW stellar age at disk
effective radius
35- 39 F5.2 [Msun/pc2] Sigma* [-1.3/3.3]? Average stellar mass density
at disk effective radius
41- 45 F5.2 [Msun/yr] SFR [-2.1/1.8] Integrated SFR
47- 50 F4.1 --- MType [1/10] Morphological type
52- 56 F5.2 [Sun] LW-Z [-0.5/0.02]? Average LW stellar
metallicity at disk effective radius
58- 63 F6.2 km/s sigma0 [0/280] Central stellar velocity dispersion
65- 69 F5.2 [-] [O/H] [-0.4/0.5]? Slope of the oxygen abundance
gradient
71- 75 F5.2 [1/Gyr] sSFR [-2.8/1.2] Specific star formation rate
77- 82 F6.3 --- SFR-Zg [-0.2/0.11] Slope of the local SFR-Zg
relation
84- 88 F5.3 --- e_SFR-Zg [0.001/0.4] SFR-Zg uncertainty
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 08-Feb-2021