J/ApJ/809/91 Outflows in sodium excess objects (Park+, 2015)
Outflows in sodium excess objects.
Park J., Jeong H., Yi S.K.
<Astrophys. J., 809, 91 (2015)>
=2015ApJ...809...91P 2015ApJ...809...91P (SIMBAD/NED BibCode)
ADC_Keywords: Abundances ; Galaxies, spectra ; Photometry, SDSS ; Morphology ;
Redshifts
Keywords: catalogs; galaxies: abundances;
galaxies: elliptical and lenticular, cD; galaxies: evolution;
galaxies: spiral; galaxies: stellar content
Abstract:
Van Dokkum and Conroy (2010Natur.468..940V 2010Natur.468..940V) revisited the unexpectedly
strong NaI lines at 8200Å found in some giant elliptical galaxies
and interpreted them as evidence for an unusually bottom-heavy initial
mass function. Jeong et al. (2013, J/ApJS/208/7) later found a large
population of galaxies showing equally extraordinary Na D doublet
absorption lines at 5900Å (Na D excess objects: NEOs) and showed
that their origins can be different for different types of galaxies.
While a Na D excess seems to be related to the interstellar medium
(ISM) in late-type galaxies, smooth-looking early-type NEOs show
little or no dust extinction and hence no compelling signs of ISM
contributions. To further test this finding, we measured the Doppler
components in the Na D lines. We hypothesized that the ISM would have
a better (albeit not definite) chance of showing a blueshift Doppler
departure from the bulk of the stellar population due to outflow
caused by either star formation or AGN activities. Many of the
late-type NEOs clearly show blueshift in their Na D lines, which is
consistent with the former interpretation that the Na D excess found
in them is related to gas outflow caused by star formation. On the
contrary, smooth-looking early-type NEOs do not show any notable
Doppler components, which is also consistent with the interpretation
of Jeong et al. that the Na D excess in early-type NEOs is likely not
related to ISM activities but is purely stellar in origin.
Description:
The parent sample for this study is the Na D excess objects (NEOs)
from J13 (Jeong+, 2013, J/ApJS/208/7). The J13 sample is drawn from
the SDSS DR7 in the redshift range of 0.00≤z≤0.08 by applying an
absolute r-band magnitude cut-off of -20.5 to obtain a volume-limited
sample and signal-to-noise ratio (S/N) cut-off of 20 to guarantee high
quality spectroscopic data.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 156 1995 The catalog of Na D excess objects;
from the erratum published in 2018, ApJ, 869, 88
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See also:
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
J/MNRAS/451/634 : ExoMol line lists for NaH and NaD (Rivlin+, 2015)
J/ApJS/208/7 : Sodium excess objects. I. SDSS-DR7 (Jeong+, 2013)
J/ApJS/94/687 : Old stellar populations. V. (Worthey+, 1994)
http://www.sdss.org/ : SDSS home page
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 18 I18 --- ObjID SDSS-DR7 object identifier
20- 21 I2 h RAh Hour of Right Ascension (J2000)
23- 24 I2 min RAm Minute of Right Ascension (J2000)
26- 30 F5.2 s RAs Second of Right Ascension (J2000)
32 A1 --- DE- Sign of the Declination (J2000)
33- 34 I2 deg DEd Degree of Declination (J2000)
36- 37 I2 arcmin DEm Arcminute of Declination (J2000)
39- 42 F4.1 arcsec DEs Arcsecond of Declination (J2000)
44- 49 F6.4 --- z [0.007/0.08] Redshift
51- 56 F6.2 mag rMag [-23.7/-20.7] SDSS absolute r band magnitude
58- 61 F4.2 mag u-r [1.2/6.9] SDSS (u-r) color index
63- 66 F4.2 --- fNaD [0/4.3] NaD excess index
68- 71 F4.2 0.1nm NaD [2/9.8] Observed NaD line strength;
Angstroms (1)
73- 77 F5.2 --- fMgb [-0.6/44.4] Mgb excess index
79- 84 F6.2 0.1nm Mgb [0.6/170] Observed Mgb line strength;
Angstroms (1)
86- 90 F5.2 --- fFe [-0.8/1.8] Fe5270 excess index
92- 96 F5.2 0.1nm Fe [0.4/5.5] Observed Fe5270 line strength;
Angstroms (1)
98-102 F5.2 --- fHb [-0.6/0.4] Hβ excess index
104-108 F5.2 0.1nm Hb [0.9/5] Observed Hβ line strength;
Angstroms (1)
110-113 A4 --- Morph Morphology (2)
115-116 A2 --- Class BPT class; emission line classification (3)
118-121 F4.2 --- a1 [0.1/0.6] Most probable value of a1 (4)
123-126 F4.2 --- a2 [0.08/0.6] Most probable value of a2 (4)
128-133 F6.1 0.1nm mu1 [5887.5/5895.2] Most probable value of mu1;
Angstroms (4)
135-140 F6.1 0.1nm mu2 [5892.8/5901.6] Most probable value of mu2;
Angstroms (4)
142-144 F3.1 0.1nm sig [0.8/5.5] Most probable value of sigma
(Standard deviation of Gaussian component;
Angstroms)
146-148 F3.1 --- gam [0.5/3.7] Most probable value of gamma (5)
150-154 F5.1 --- chi2 [0.1/711] Reduced chi-square
156 A1 --- Set [CN] Sample (N: NEO or C: Control)
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Note (1): Observed line strength from OSSY catalog
(Oh et al. 2011ApJS..195...13O 2011ApJS..195...13O).
Note (2): Morphology as follows:
oETG = ordinary early-type Na D excess object (NEO)
pETG = peculiar early-type Na D excess object (NEO)
oLTG = ordinary late-type Na D excess object (NEO)
pLTG = peculiar late-type Na D excess object (NEO)
cETG = early-type control galaxy
cLTG = late-type control galaxy
Note (3): Emission line classification by the BPT diagnostic as follows:
SF = Star-forming;
Co = Composite (i.e., hosting both star formation and AGN activity);
Se = Seyfert;
LI = Liner;
NE = non-emission line galaxy: object that do not have A/N>3 in
the four main lines.
Note (4): See equation (2) in section 3.1:
y=a1.exp(-((x-µ1)2/2σ2))+a2.exp((x-µ2)2/2σ2))
where a and σ represent the line depth and width of the Na D
absorption feature, respectively, and µ is the position of the
centroid.
Note (5): FWHM of Lorentzian component.
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History:
From electronic version of the journal
13-Jan-2016: Insert into VizieR
04-Feb-2019: Table 1 corrected via erratum. (Some declination sign were
erroneous - the rest of the table, including the SDSS column and the links
toward Simbad and NED were correct since based on SDSS objid and not
on coordinates).
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 08-Dec-2015