J/A+A/666/A161 Spatially resolved kinematics in starburst galaxies (Bik+, 2022)
Spatially resolved gas and stellar kinematics in compact starburst galaxies.
Bik A., Ostlin G., Hayes M., Melinder J., Menacho V.
<Astron. Astrophys. 666, A161 (2022)>
=2022A&A...666A.161B 2022A&A...666A.161B (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, IR ; Galaxies, spectra ; Velocity dispersion ;
Spectroscopy
Keywords: galaxies: kinematics and dynamics - galaxies: starburst -
galaxies: ISM - infrared: galaxies - ISM: kinematics and dynamics -
stars: kinematics and dynamics
Abstract:
The kinematics of galaxies provide valuable insights into their
physics and assembly history. Kinematics are governed not only by the
gravitational potential, but also by merger events and stellar
feedback processes such as stellar winds and supernova explosions. We
aim to identify what governs the kinematics in a sample of
SDSS-selected nearby starburst galaxies, by obtaining spatially
resolved measurements of the gas and stellar kinematics. We obtained
near-infrared integral-field K-band spectroscopy with VLT/SINFONI for
15 compact starburst galaxies. We derived the integrated as well as
spatially resolved stellar and gas kinematics. The stellar kinematics
were derived from the CO absorption bands, and Paα and
Brγ emission lines were used for the gas kinematics. Based on
the integrated spectra, we find that the majority of galaxies have gas
and stellar velocity dispersion that are comparable. A spatially
resolved comparison shows that the six galaxies that deviate show
evidence for a bulge or stellar feedback. Two galaxies are identified
as mergers based on their double-peaked emission lines. In our sample,
we find a negative correlation between the ratio of the rotational
velocity over the velocity dispersion (vrot/σ) and the star
formation rate surface density. We propose a scenario where the global
kinematics of the galaxies are determined by gravitational
instabilities that affect both the stars and gas. This process could
be driven by mergers or accretion events. Effects of stellar feedback
on the ionised gas are more localised and detected only in the
spatially resolved analysis. The mass derived from the velocity
dispersion provides a reliable mass even if the galaxy cannot be
spatially resolved. The technique used in this paper is applicable to
galaxies at low and high redshift with the next generation of
infrared-focussed telescopes (JWST and ELT).
Description:
The observations of the compact starburst galaxies (table1.dat) were
performed using the SINFONI integral field instrument, mounted at UT4
(Yepun) of the VLT at Paranal, Chile. The observations were carried
out in service mode between 2016-05-19 and 2016-08-21.
For each of the 15 galaxies discussed in this paper we provide the
reduced VLT/SINFONI datacube. The observations and reduction are
described in Sect. 3. Additionally, the Voronoi tesselated flux maps,
velocity maps and velocity dispersion maps are provided. These files
are used to produce Figs. 9, 10 and all appendix figures (See Sect. 4
for the technical details).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 102 15 Galaxy sample
list.dat 145 45 List of fits files
fits/* . 45 Individual fits files
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Name Name (SDSS JHHMM+DDMM)
17- 18 I2 h RAh Right ascension (J2000)
20- 21 I2 min RAm Right ascension (J2000)
23- 27 F5.2 s RAs Right ascension (J2000)
29 A1 --- DE- Declination sign (J2000)
30- 31 I2 deg DEd Declination (J2000)
33- 34 I2 arcmin DEm Declination (J2000)
36- 40 F5.2 arcsec DEs Declination (J2000)
42- 51 F10.8 --- z Redshift
53- 56 F4.2 arcsec R50 Petrosian radius R50 in r band
58- 61 F4.2 arcsec e_R50 rms uncertainty on R50
63- 67 F5.1 0.1nm EWHa Hα equivalent width
69- 71 F3.1 0.1nm e_EWHa rms uncertainty on EWHa
73- 77 F5.2 mag Ksmag SDSS Ks magnitude
79-102 A24 --- SDSS SDSS name (SDSS JHHMMSS.ss+DDMMSS.s)
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 24 F5.3 arcsec/pix scale ? Scale of the image
26- 27 I2 --- Nx Number of pixels along X-axis
29- 30 I2 --- Ny Number of pixels along Y-axis
32- 35 I4 --- Nz ? Number of slices for the datacubes
37- 60 A24 "datime" Obs.date Observation date
62- 68 F7.5 0.1nm bWAVE ? Lower value of wavelength interval
70- 76 F7.5 0.1nm BWAVE ? Upper value of wavelength interval
78- 85 F8.6 0.1nm dWAVE ? Wavelength resolution
87- 92 I6 Kibyte size Size of FITS file
94-105 A12 --- FileName Name of FITS file, in subdirectory fits
107-145 A39 --- Title Title of the FITS file
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Acknowledgements:
Arjan Bik, arjan.bik(at)astro.su.se
(End) Patricia Vannier [CDS] 30-Aug-2022