J/A+A/632/A78 A case study of the HI content of HCG 16 (Jones+, 2019)
Evolution of compact groups from intermediate to final stages.
A case study of the HI content of HCG 16.
Jones M.G., Verdes-Montenegro L., Damas-Segovia A., Borthakur S., Yun M. S.,
del Olmo A., Perea J., Roman J., Luna, S., Lopez Gutierrez D., Williams B.,
Vogt F.P.A., Garrido J., Sanchez S., Cannon J., Ramirez-Moreta P.
<Astron. Astrophys. 632, A78 (2019)>
=2019A&A...632A..78J 2019A&A...632A..78J (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, spectra ; H I data ; Radio lines ; Galaxies, nearby
Keywords: galaxies: groups: individual: HCG 16 - galaxies: interactions -
galaxies: evolution - galaxies: ISM - radio lines: galaxies
Abstract:
Hickson Compact Group (HCG) 16 is a prototypical compact group of
galaxies in an intermediate stage of the evolutionary sequence
proposed by Verdes-Montenegro et al. (2001A&A...377..812V 2001A&A...377..812V), where its
galaxies are losing gas to the intra-group medium (IGrM). The group
hosts galaxies that are HI-normal, HI-poor, centrally active with both
AGN and starbursts, as well as a likely new member and a 160kpc long
HI tidal feature. Despite being a well-studied group at all
wavelengths, no previous study of HCG 16 has focused on its
extraordinary HI component.
The characteristics of HCG 16 make it an ideal case study for
exploring which processes are likely to dominate the late stages of
evolution in compact groups, and ultimately determine their end
states. In order to build a coherent picture of the evolution of this
group we make use of the multi-wavelength data available, but focus
particularly on HI as a tracer of interactions and evolutionary phase.
We reprocess archival VLA L-band observations of HCG 16 using the
multi-scale CLEAN algorithm to accurately recover diffuse features.
Tidal features and galaxies are separated in 3 dimensions using the
SlicerAstro package. The HI deficiency of the separated galaxies is
assessed against the benchmark of recent scaling relations of isolated
galaxies. This work has been performed with particular attention to
reproducibility and is accompanied by a complete workflow to reproduce
all the final data products, figures, and results.
Despite the clear disruption of the HI component of HCG 16 we find
that it is not globally HI deficient, even though HCG 16a and b have
lost the majority of their HI and almost 50% of the group's HI is in
the IGrM. The HI content of HCG 16d shows highly disturbed kinematics,
with only a marginal velocity gradient that is almost perpendicular to
its optical major axis. The ∼160kpc long tail extending towards the
South-East appears to be part of an even larger structure which
spatially and kinematically connects NGC 848 to the North-West corner
of the group.
This study indicates that in the recent past (1Gyr) galaxies HCG 16a
and b likely underwent major interactions that unbound gas without
triggering significant star formation. This gas was then swept away by
a high speed, close encounter with NGC 848. The starburst events HCG
16c and d, likely initiated by their mutual interaction, have
triggered galactic winds which, in the case of HCG 16d, appears to
have disrupted its HI reservoir.
The tidal features still connected to all these galaxies indicate that
more HI will soon be lost to the IGrM, while that which remains in the
discs will likely be consumed by star formation episodes triggered by
their on-going interaction. This is expected to result in a collection
of gas-poor galaxies embedded in a diffuse HI structure, which will
gradually (over several Gyr) be evaporated by the UV background,
resembling the final stage of the evolutionary model of compact
groups.
Description:
Here we present the data tables from the paper which cover the optical
and HI properties of the galaxies in HCG16, as well as their gas
consumption timescales.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 56 6 Summary of optical properties of HCG 16 galaxies
table2.dat 46 14 Summary of HI properties of HCG 16 galaxies
table3.dat 31 4 Gas masses and gas consumption timescale
list.dat 138 1 Information on datacude
fits/* . 1 Datacube
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See also:
VII/213 : Hickson's compact groups of Galaxies (Hickson+ 1982-1994)
VII/155 : Third reference cat. of bright galaxies
(de Vaucouleurs+ 1991)
J/A+A/540/A96 : Molecular gas in HCGs (Martinez-Badenes+ 2012)
J/MNRAS/459/2948 : Compact group galaxies UV and IR SFR (Lenkic+ 2016)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- HCG ? HCG number (VII/213)
4 A1 --- m_HCG [a-d] m_HCG member galaxy (VII/213)
6- 12 A7 --- Name Other common name of galaxy
14 I1 h RAh Right ascension (J2000)
16- 17 I2 min RAm Right ascension (J2000)
19- 22 F4.1 s RAs Right ascension (J2000)
24 A1 --- DE- Declination sign (J2000)
25- 26 I2 deg DEd Declination (J2000)
28- 29 I2 arcmin DEm Declination (J2000)
31- 32 I2 arcsec DEs Declination (J2000)
34- 37 A4 --- MType Morphological type (from RC3)
39- 42 I4 km/s HRV Heliocentric radial velocity (from optical lines)
44- 45 I2 arcsec D25 Major isophotal diameter at 25mag/arcsec2
47- 51 F5.2 [Lsun] logLB B-band luminosity relative to solar
53- 56 F4.2 [Lsun] e_logLB Uncertainty in B-band luminosity
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- HCG ? HCG number (VII/213)
4 A1 --- m_HCG [a-d] m_HCG member galaxy (VII/213)
6- 16 A11 --- Name Other name of galaxy/source
18- 21 F4.2 Jy.km/s SHI Integrated HI flux
23- 26 I4 km/s vbar Mean velocity of HI line
28- 30 I3 km/s e_vbar Standard deviation of HI line
32- 35 F4.2 [Msun] logMHI HI mass in solar masses
37- 41 F5.2 --- HIdef ? HI deficiency (dex)
43- 46 F4.2 --- e_HIdef ? Uncertainty in HI deficiency (dex)
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- HCG HCG number (VII/213)
4 A1 --- m_HCG [a-d] m_HCG member galaxy (VII/213)
6- 10 F5.2 [Msun] logMS Stellar mass in solar masses (from Lenkic et
al., 2916, Cat. J/MNRAS/459/2948)
12- 15 F4.2 [Msun] logMHI HI mass in solar masses
17- 21 F5.2 [Msun] logMH2 Molecular hydrogen mass in solar masses
(from Martinex-Badenes et al., 2012,
Cat. J/A+A/540/A96)
23- 27 F5.2 Msun/yr SFR Star formation rate (from Lenkicet al., 2916,
Cat. J/MNRAS/459/2948)
29- 31 F3.1 Gyr Tcon Gas (atomic + molecular) consumption timescale
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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- 22 I3 --- Nx Number of pixels along X-axis
24- 26 I3 --- Ny Number of pixels along Y-axis
28- 29 I2 --- Nz Number of pixels along Z-axis
31- 56 A26 "datime" Obs.date Observation date
58- 68 E11.5 m/s bVRAD Lower value of VRAD interval
70- 80 E11.5 m/s BVRAD Upper value of VRAD interval
82- 88 F7.1 m/s dVRAD VRAD resolution
90- 94 I5 Kibyte size Size of FITS file
96-122 A27 --- FileName Name of FITS file, in subdirectory fits
124-138 A15 --- Title Title of the FITS file
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Acknowledgements:
Michael Jones, mjones(at)iaa.es
(End) Michael Jones [IAA, Spain], Patricia Vannier [CDS] 11-Oct-2019