J/A+A/675/A59 HI in NGC 3100 (Maccagni+, 2023)
The AGN fuelling/feedback cycle in nearby radio galaxies.
V. The cold atomic gas of NGC 3100 and its group.
Maccagni F.M., Ruffa I., Loni A., Prandoni I., Ragusa R., Kleiner D.,
Serra P., Iodice E., Spavone M.
<Astron. Astrophys. 675, A59 (2023)>
=2023A&A...675A..59M 2023A&A...675A..59M (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, radio ; Radio sources
Keywords: galaxies: individual: NGC 3100 - galaxies: active - galaxies: ISM -
galaxies: kinematics and dynamics - galaxies: groups: general
Abstract:
We present Australia Compact Telescope Array (ATCA) 21-cm observations
of the nearby low-excitation radio galaxy (LERG) NGC 3100. This is the
brightest galaxy of a loose group and hosts a young (∼2Myr)
radio source. The ATCA observations reveal for the first time the
presence of neutral hydrogen (HI) gas in absorption in the centre of
this radio galaxy, and in emission in two low-mass galaxies of the
group and in a diffuse dark cloud in the proximity of NGC 3100. The
sensitivity to low-column density gas (NHI∼1019cm-2) allows us
to reveal asymmetries in the periphery of most the HI-detected
galaxies, suggesting that tidal interactions may be on-going. The
diffuse cloud does not show a stellar counterpart down to
27mag/arcsec2 and could be the remnant of these interactions. The
analysis of the HI absorption complex in NGC 3100 indicates that the
atomic phase of the hydrogen is distributed as its molecular phase
(observed at arcsecond resolution through several carbon monoxide
emission lines). We suggest that the interactions occurring within the
group are causing turbulent cold gas clouds in the intra-group medium
to be slowly accreted towards the centre of NGC 3100. This caused the
recent formation of the cold circum-nuclear disk which is likely
sustaining the young nuclear activity.
Description:
The ATCA observations of NGC 3100 were taken in three separate runs of
12 hours each, with different array configurations. The observations
were centred at the HI frequency of the systemic velocity of the
galaxy, 1409.13MHz. The Compact Array Broadband Backend (CABB) of the
telescope provides a total bandwidth of 64MHz over 2048 channels (dual
polarisation). At the HI frequency, in the Local Universe, the channel
width is ~=6.6km/s.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 75 8 HI properties of the sources in the
NGC 3100 group
table3.dat 42 7 Optical properties of the HI detections in
the NGC 3100 group
list.dat 169 1 Information of fits datacube
fits/* . 1 Fits datacube
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Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Name Source name of the HI detections in the
NGC3100 group
13- 14 I2 h RAh Right Ascension (J2000)
16- 17 I2 min RAm Right Ascension (J2000)
19- 23 F5.2 s RAs Right Ascension (J2000)
25 A1 --- DE- Declination sign (J2000)
26- 27 I2 deg DEd Declination (J2000)
29- 30 I2 arcmin DEm Declination (J2000)
32- 35 F4.1 arcsec DEs Declination (J2000)
37- 40 I4 km/s Vsys HI systemic velocity
42- 46 F5.1 km/s W50 Line-width (FWHM) at 50% of the peak
48- 52 F5.1 km/s W80 Line-width at 20% of the peak
54- 59 F6.3 Jy.km/s FHI Integrated HI flux of the source
60 A1 --- n_FHI [*] Note on FHI (1)
62- 67 E6.2 Msun MHI Total HI mass of the source of lower value
of mass interval
68 A1 --- --- [-]
69- 74 E6.2 Msun MHIup ? Upper value of total HI mass of the source
75 A1 --- n_MHI [*] Note on MHD (2)
--------------------------------------------------------------------------------
Note (1): Note as follows:
* = corresponds to an optical depth of τ=0.114
Note (2): Note as follows:
* = mass range estimated with different assumptions on the real
extent of the HI gas detected in absorption
-------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
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1- 11 A11 --- Name Source name of the HI detections in the
NGC3100 group
13- 17 F5.2 mag gmag VEGAS magnitude in the g filter (1)
19- 23 F5.2 mag rmag VEGAS magnitude in the r filter (1)
25- 28 F4.2 mag g-r g-r color
30- 35 F6.3 10+10Msun Mstarg Stellar mass inferred from g magnitude
37- 42 F6.3 10+10Msun Mstarr Stellar mass inferred from r magnitude
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Note (1): The mean errors on the magnitudes are 0.05 and 0.04 for the g and r
bands, respectively.
-------------------------------------------------------------------------------
Byte-by-byte Description of file: list.dat
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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- 22 I3 --- Nx Number of pixels along X-axis
24- 26 I3 --- Ny Number of pixels along Y-axis
28- 30 I3 --- Nz Number of slices
32- 52 A21 "datime" Obs.date Observation date
54- 62 E9.4 m/s bVELO-HEL Lower value of heliocentric velocity interval
64- 74 E11.4 m/s BVELO-HEL Upper value of heliocentric velocity interval
76- 82 F7.2 m/s dVELO-HEL Helicoentric velocity resolution
84- 89 I6 Kibyte size Size of FITS file
91-108 A18 --- FileName Name of FITS file, in subdirectory fits
110-169 A60 --- Title Title of the FITS file
--------------------------------------------------------------------------------
Acknowledgements:
Filippo Maccagni, maccagni(at)astron.nl
References:
Ruffa et al., Paper I 2019MNRAS.484.4239R 2019MNRAS.484.4239R
Ruffa et al., Paper II 2019MNRAS.489.3739R 2019MNRAS.489.3739R
Ruffa et al., Paper III 2020MNRAS.499.5719R 2020MNRAS.499.5719R
Ruffa et al., Paper IV 2022MNRAS.510.4485R 2022MNRAS.510.4485R
(End) Patricia Vannier [CDS] 21-Jun-2023