J/A+A/634/A95 Star formation in the blue compact dwarf Mrk 900 (Cairos+, 2020)
Understanding star formation and feedback in small galaxies. The case of the
blue compact dwar Mrk 900.
Cairos L.M., Gonzalez-Perez J.N.
<Astron. Astrophys. 634, A95 (2020)>
=2020A&A...634A..95C 2020A&A...634A..95C (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, spectra
Keywords: galaxies: dwarf - galaxies: individual: Mrk900 - galaxies: starburst -
galaxies: stellar content: galaxies: star formation -
galaxies: abundances
Abstract:
Low-luminosity, active star-forming blue compact galaxies (BCGs) are
excellent laboratories for investigating the process of star formation
on galactic scales and probing the interplay between massive stars and
the surrounding interstellar (or intergalactic) medium. We
investigated the morphology, structure, and stellar content of the
Blue Compact Galaxy Mrk 900, combining optical integral field
observations obtained with VIMOS at the VLT and deep broad-band
photometry taken at the 2.5 m NOT telescope. From the integral field
data, we built continuum, emission, and diagnostic line ratio maps and
produced velocity and velocity dispersion maps. We also generated the
integrated spectrum of the major HII regions and the nuclear area to
determine reliable physical parameters and oxygen abundances. The
broad-band data, tracing the galaxy up to radius 4 kpc, allowed us to
investigate the properties of the low surface brightness underlying
stellar host. We disentangle two different stellar components in Mrk
900: a young population, which resolves into individual stellar
clusters with ages ∼5.5-6.6Myr and extends about 1 kpc along the
galaxy minor axis, is placed on top of a rather red and regular shaped
underlying stellar host, several Gyr old. We find evidence of a
substantial amount of dust and an inhomogeneous extinction pattern,
with a dust lane crossing the central starburst. Mrk 900 displays
overall rotation, although distorted in the central, starburst
regions; the dispersion velocity map is highly inhomogeneous, with
values increasing up to 60km/s at the periphery of the SF regions,
where we also find hints of the presence of shocks. Our observational
results point to an interaction or merger with a low-mass object or
infalling gas as plausible trigger mechanisms for the present
starburst event.
Description:
Reduced datacubes for Mrk 900 of observations with VLT-VIMOS with the
blue and the orange grism. The wavelength range are 4150-6200Å, with
a dispersion of 0.54Å/pix, for the blue grism datacube and
5250-7400Å, with a dispersion of 0.62Å/pix, for data taken with
the orange grism. Each spaxel is 0.67x0.67arcsec2 and the flux units
are 10^-16 erg/cm2/s/Å. The observations were performed in Aug.
2007.
Broadband images taken with the Nordic optical telescope (NOT) with
the instrument ALFOSC in the B, V, and R filters. The field of view is
6.5x6.5arcmin2, with a pixel scale of 0.188-arcsec/pix. The
observations were performed in August 2005.
Objects:
------------------------------------------------
RA (2000) DE Designation(s)
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21 29 59.63 +02 24 51.8 Mkn 900 = NGC 7077
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File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
list.dat 153 5 List of fits files
fits/* . 5 Individual fits files
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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- 23 I4 --- Nx Number of pixels along X-axis
25- 28 I4 --- Ny Number of pixels along Y-axis
30- 33 I4 --- Nz ? Number of slices for the datacubes
35- 53 A19 "datime" Obs.date Observation date
55- 61 F7.2 0.1nm blambda ? Lower value of wavelength interval,
for the datacubes
63- 69 F7.2 0.1nm Blambda ? Upper value of wavelength interval,
for the datacubes
71- 74 F4.2 0.1nm dlambda ? Wavelength resolution, for the datacubes
76- 80 I5 Kibyte size Size of FITS file
82- 93 A12 --- FileName Name of FITS file, in subdirectory fits
95-153 A59 --- Title Title of the FITS file
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Acknowledgements:
Luz-Marina Cairos, luzma(at)astro.physik.uni-goettingen.de
(End) L.M. Cairos [Univ. Gottingen], Patricia Vannier [CDS] 04-Feb-2020