J/A+A/652/A108 The Fourcade-Figueroa galaxy (Saponara+, 2021)
The Fourcade-Figueroa galaxy: a clearly disrupted superthin edge-on galaxy.
Saponara J., Kamphuis P., Koribalski B.S., Benaglia P.
<Astron. Astrophys. 652, A108 (2021)>
=2021A&A...652A.108S 2021A&A...652A.108S (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; H I data
Keywords: galaxies: groups: individual: ESO 270-G017 -
galaxies: interactions - radio lines: galaxies
Abstract:
Studies of the stellar and the HI gas kinematics in dwarf and Low
Surface Brightness (LSB) galaxies are essential for deriving
constraints on their dark matter distribution. Moreover, a key
component to unveil in the evolution of LSBs is why some of them can
be classified as superthin. We aim to investigate the nature of the
proto-typical superthin galaxy Fourcade-Figueroa (FF), to understand
the role played by the dark matter halo in forming its superthin shape
and to investigate the mechanism that explains the observed disruption
in the approaching side of the galaxy. Combining new HI 21-cm
observations obtained with the Giant Metrewave Radio Telescope with
archival data from the Australia Telescope Compact Array we were able
to obtain sensitive HI observations of the FF galaxy. These data were
modeled with a 3D tilted ring model in order to derive the rotation
curve and surface brightness density of the neutral hydrogen. We
subsequently used this model, combined with a stellar profile from the
literature, to derive the radial distribution of the dark matter in
the FF galaxy. Additionally, we used a more direct measurement of the
vertical HI gas distribution as a function of the galactocentric
radius to determine the flaring of the gas disk. For the FF galaxy the
Navarro-Frenk-White dark matter distribution provides the best fit to
the observed rotation curve. However, the differences with a
pseudo-isothermal halo are small. Both models indicate that the core
of the dark matter halo is compact. Even though the FF galaxy
classifies as superthin, the gas thickness about the galactic centre
exhibits a steep flaring of the gas which is in agreement with the
edge of the stellar disk. Besides, FF is clearly disrupted towards its
north-west-side, clearly observed at both, optical and HI wavelengths.
As suggested previously in the literature, the compact dark matter
halo might be the main responsible for the superthin structure of the
stellar disk in FF. This idea is strengthened through the detection of
the mentioned disruption; the fact that the galaxy is disturbed also
seems to support the idea that it is not isolation that cause its
superthin structure.
Description:
The Fourcade-Figueroa galaxy was observed in 2015 and 2016 for almost
fifteen hours with the Giant Metrewave Radio Telescope. We used 3C286
as flux calibrator.
In addition, we reduced 27.6 of archival data observed with the
Australia Telescope Compact Array. The available fits file is the
combination of both interferometers datasets.
Objects:
----------------------------------------------------------
RA (2000) DE Designation(s)
----------------------------------------------------------
13 34 47.3 -45 32 51 Fourcade-Figueroa = ESO 270-G017
----------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
list.dat 131 1 Information on fits datacube
fits/* . 1 Fist datacube
--------------------------------------------------------------------------------
Byte-by-byte Description of file: list.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
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- 31 I2 --- Nz Number of slices
33- 53 A21 "datime" Obs.date Observation date
55- 57 I3 km/s bVELO-HEL Lower value of heliocentric velocity interval
59- 61 I3 km/s BVELO-HEL Upper value of heliocentric velocity interval
63 I1 km/s dVELO-HEL Heliocentric velocity resolution
65- 70 I6 Kibyte size Size of FITS file
72- 96 A25 --- FileName Name of FITS file, in subdirectory fits
98-131 A34 --- Title Title of the FITS file
--------------------------------------------------------------------------------
Acknowledgements:
Saponara Juliana, jsaponara(at)iar-conicet.gov.ar
(End) Patricia Vannier [CDS] 09-Jun-2021