J/A+A/XXX/XXX      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., Roman J., Luna, S., Lopez Gutierrez D., Williams B.,
    Vogt F.P.A., Garrido J., Sanchez S., Cannon J., Ramirez-Moreta P.
   <Astron. Astrophys. XXX, XXX (2019)>
================================================================================
ADC_Keywords: Galaxies, spectra ; H I data ; Radio lines ; Galaxies, nearby
Keywords: 

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. 2001, 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 160 kpc 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 $\sim$160 kpc 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 (1 Gyr) 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:
--------------------------------------------------------------------------------
FileName    Lrecl  Records   Explanations
--------------------------------------------------------------------------------
ReadMe         80        .   This file
table1.dat     57        6   Summary of optical properties of HCG 16 galaxies
table2.dat     47       14   Summary of HI properties of HCG 16 galaxies
table3.dat     32        4   Gas masses and gas consumption timescale
--------------------------------------------------------------------------------

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/MNRAS/459/2948: Compact group galaxies UV and IR SFR (Lenkic+ 2016) 
J/A+A/540/A96   : Molecular gas in HCGs (Martinez-Badenes+ 2012) 

Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units   Label     Explanations
--------------------------------------------------------------------------------
 1- 2  I2    ---     HCG       ? [1/100] HCG number (VII/213)
 4     A1    ---     m_HCG     ? [a-i] m_HCG member galaxy (VII/213)
 6-12  A7    ---     name      Other common name of galaxy
14     I1    h       RAh       [0,24[ RA (J2000) hours
16-17  I2    min     RAm       [0,60[ RA (J2000) minutes
19-22  F4.1  s       RAs       [0,60[ RA (J2000) seconds
24     A1    ---     DE-       [+-] Sign of declination
25-26  I2    deg     DEd       [0,90[ Dec (J2000) degrees
28-29  I2    arcmin  DEm       [0,60[ Dec (J2000) arcminutes
31-32  I2    arcsec  DEs       [0,60[ Dec (J2000) arcseconds
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 25 mag arcsec^-2
47-51  F5.2  [Lsun]  logLB     B-band luminosity relative to solar
53-56  F4.2  ---     e_logLB   Uncertainty in B-band luminosity (dex)

Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units   Label     Explanations
--------------------------------------------------------------------------------
 1- 2  I2    ---     HCG       ? [1/100] HCG number (VII/213)
 4     A1    ---     m_HCG     ? [a-i] 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_v       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)

Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units   Label     Explanations
--------------------------------------------------------------------------------
 1- 2  I2    ---     HCG       [1/100] HCG number (VII/213)
 4     A1    ---     m_HCG     [a-i] m_HCG member galaxy (VII/213)
 6-10  F5.2  [Msun]  logMS     Stellar mass in solar masses (from Lenkic+ 2016)
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+ 2012)
23-27  F5.2  Msun/yr SFR       Star formation rate (from Lenkic+ 2016)
29-31  F3.1  Gyr     Tcon      Gas (atomic + molecular) consumption timescale

================================================================================
(End)    Jones+2019                                                   2019-10-10
