J/MNRAS/499/4370 Star formation in perturbed galaxies I (Morales-Vargas+, 2020)
Star formation in CALIFA survey perturbed galaxies
I. Effects of tidal interactions.
Morales-Vargas A., Torres-Papaqui J.P., Rosales-Ortega F.F., Sanchez S.F.,
Chow-Martinez M., Ortega-Minakata R.A., Trejo-Alonso J.J.,
Robleto-Orus A.C., Romero-Cruz F.J., Neri-Larios D.M.,
(the CALIFA Survey Collaboration)
<Mon. Not. R. Astron. Soc., 499, 4370-4393 (2020)>
=2020MNRAS.499.4370M 2020MNRAS.499.4370M (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies ; Star Forming Region ; Morphology ; Optical
Keywords: galaxies: evolution - galaxies: interactions -
galaxies: star formation - galaxies: statistics
Abstract:
We explore the effects of tidal interactions on star formation (SF) by
analysing a sample of CALIFA survey galaxies. The sample consists of
tidally and non-tidally perturbed galaxies whose star-forming regions
are paired at the closest stellar mass surface densities, even between
the same galaxy types. The regions are then compared, both on the
resolved star-formation main sequence (SFMS) plane and in annular
property profiles. Star-forming regions in tidally perturbed galaxies
exhibit flatter SFMS slopes compared to star-forming regions in
non-tidally perturbed galaxies. Despite the fact that the annular
profiles show star-forming regions in tidally perturbed galaxies as
being mostly older, their SF properties are never reduced against
those of non-tidally perturbed galaxies. Star-forming regions in
non-tidally perturbed galaxies are better candidates for SF
suppression (quenching). The lowered SF with increasing stellar mass
density in tidally perturbed galaxies may suggest a lower dependence
of SF on stellar mass. Though the SFMS slopes, either flatter or
steeper, are found independent of stellar mass density, the effect of
global stellar mass cannot be ignored when distinguishing between
galaxy types. Since a phenomenon or property other than local/global
stellar mass may be taking part in the modulation of SF, the
integrated SF properties are related to the tidal perturbation
parameter. We find weak, but detectable, positive correlations for
perturbed galaxies suggesting that tidal perturbations induced by
close companions increase the gas accretion rates of these objects.
Description:
The Mother Sample (MS) was selected from the SDSS/DR7 photometric
catalogue to include all galaxies with an r-band isophotal diameter of
45arcsec<d<79.2arcsec (0.005<z<0.03). The selection of these
candidates is mainly based on visibility and to fit the PMAS/PPak
field of view (see Walcher et al. 2014A&A...569A...1W 2014A&A...569A...1W). The PMAS (Roth
et al. 2005PASP..117..620R 2005PASP..117..620R)/PPak (Kelz et al. 2006PASP..118..129K 2006PASP..118..129K;
Bershady & Verheijen 2010ApJ...716..198B 2010ApJ...716..198B, Cat. J/ApJ/716/198) integral
field spectrograph, mounted on the Calar Alto 3.5m telescope, was used
to perform the survey observations.
The CALIFA survey consists of 667 objects. From these, 542 are a
subset of the MS. 529 out of these 542 were observed in the widest
wavelength range. Of these, 454 objects have f estimations (Walcher et
al. 2014A&A...569A...1W 2014A&A...569A...1W). Under the criterion of Varela et al.
(2004A&A...420..873V 2004A&A...420..873V, Cat. J/A+A/420/873), i.e. f←4.5 for no
perturbation, 101 are non-tidally perturbed and 353 are tidally
perturbed.
We obtain a resolved Baldwin, Phillips & Terlevich
(1981PASP...93....5B 1981PASP...93....5B) (BPT) diagram, with a median star-forming region
fraction of 0.85, for 62 out of the 101 non-tidally perturbed objects.
This effective set of non-tidally perturbed objects is hereafter
called the control sample. To perform fair comparisons of stellar
population properties, we construct from the perturbed sample 10
subsets with 62 objects each that mimic as close as possible five
fundamental properties of the control sample. In sum, the 10 trials
have a usage of 162/231 perturbed galaxies (see Section 3.3 for
details).
Fundamental and other properties for control and perturbed objects are
showed in Table A1.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tablea1.dat 100 224 Fundamental properties for control (f←4.5) and
perturbed (f≥-4.5) objects
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See also:
J/A+A/420/873 : Properties of isolated disk galaxies (Varela+, 2004)
Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 A2 --- Sample [OC/PC] Indicates if the source is a
control object (CO) or a perturbed
object (PO)
4- 16 A13 --- Name Galaxy name
18- 22 F5.2 [Msun] logMass Logarithm of the stellar mass
24- 30 F7.5 --- z Raw redshift measured from the CALIFA
cube
32- 39 A8 --- Morph Reclassification of morphology
41- 43 A3 --- Group Morphological group (1)
45- 49 A5 --- Colour Galaxy colour determined from
colour-magnitude diagram
51- 55 A5 --- DES Dominant excitation source (BPT) (2)
57- 62 F6.4 kpc2 Surfscale Surface scale (3)
64- 67 F4.2 --- b/a Axis ratio (4)
69- 74 F6.3 --- f Tidal perturbation parameter (5)
76 A1 --- Deproj [Y/N] Indicates if a deprojection was
made (6)
78- 81 F4.2 --- FHa Hα emission distribution (7)
83- 87 F5.2 [yr] logSPAge Logarithm of the median stellar
population age
89- 92 I4 --- NSFR Number of star-forming regions
94- 100 F7.4 [Msun/yr] logSFR Logarithm of the global star formation
rate
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Note (1): Morphological group as follows:
LTS = Sbc and later types as late-type spirals (136/224)
ETS = Early-type spirals (84/224)
ET = Early-type (4/224)
Note (2): [OIII]/Hβ against [NII]/Hα (BPT diagnostic diagram,
Baldwin et al. 1981PASP...93....5B 1981PASP...93....5B).
DES as follows:
SFG = Star-forming galaxy (174/224)
TO = Transition object (43/224)
LINER = Low-ionization (nuclear) emission line region (4/224)
Sy2 = Seyfert 2 (3/224)
Note (3): Equivalence of 1 arcsec2
Note (4): Semiminor to semimajor axial ratio from light-moment analyses (see
Walcher et al. 2014A&A...569A...1W 2014A&A...569A...1W). Also cosΦ, i.e. the cosine
of the inclination angle
Note (5): The tidal perturbation parameter (f, Byrd et al. 1986A&A...166...75B 1986A&A...166...75B;
Varela et al. 2004A&A...420..873V 2004A&A...420..873V, Cat. J/A+A/420/873) is defined as:
f=log(Fprim/Fsec)=3log(R/b)+0.4(msec-mprim).
Fprim indicates the tidal force exerted by the primary galaxy;
Fsec, the internal force in the outskirts of the secondary; mprim
and msec, their respective apparent magnitudes; R, the secondary
disc radius; and b, the perigalactic distance of the primary.
Note (6): Indicates a relocation of each spaxel coordinate on a disc plane
Note (7): Radius containing 60 per cent of the Hα flux as a function of
Re (see Section 3.5)
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History:
From electronic version of the journal
References:
Morales-Vargas et al., Paper II 2021MNRAS.508.4216M 2021MNRAS.508.4216M
(End) Ana Fiallos [CDS] 08-Sep-2023