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Title: H I ASYMMETRIES IN THE ISOLATED GALAXY CIG 292

Abstract

We present Expanded Very Large Array (EVLA) D-array observations of the 21 cm line of neutral hydrogen (H I) of CIG 292, an isolated SA(s)b galaxy at a distance of {approx}24.3 Mpc. From previous H I single dish observations the galaxy was known to have a mildly asymmetric H I profile (A {sub flux} = 1.23 {+-} 0.3). Our EVLA observations show there is {approx}12% more H I projected south of the optical center (approaching velocities) than in the north (receding velocities), despite the H I extending {approx}16% further to the north than the south. The H I projected within the optical disk must have been perturbed within the H I relaxation time ({approx}10{sup 8} yr) which implies that this cannot have been caused by any of the three nearest companions, as their distance ({approx}0.5 Mpc) is too large. Neither H I-rich companions nor tidal tails were found within our field of view and velocity range covered. Our kinematical data suggest that the inner part harbors an oval distortion whereas the outer regions show signs of a modest warp. The mild asymmetry in the H I global profile thus actually masks stronger asymmetries in the two-dimensional distributions of gas andmore » star-forming regions in this galaxy. Since the galaxy is isolated, this must predominantly be due to processes related to its formation and secular evolution.« less

Authors:
; ; ; ;  [1]; ;  [2]; ;  [3];  [4];  [5];  [6]
  1. Instituto de Astrofisica de Andalucia (CSIC), Glorieta de AstronomIa s/n, 18008 Granada (Spain)
  2. Centre for Astrophysics, University of Hertfordshire, Hatfield, Herts AL10 9AB (United Kingdom)
  3. Laboratoire d'Astrophysique de Marseille (LAM), UMR6110, CNRS/Universite de Provence/CNRS, Technopole de Marseille Etoile, 38 rue Frederic Joliot Curie, 13388 Marseille CEDEX 13 (France)
  4. National Astronomical Observatory of Japan (NAOJ), 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)
  5. Departamento de Fisica Teorica y del Cosmos, Facultad de Ciencias, Universidad de Granada (Spain)
  6. Department of Astronomy, University of Massachusetts, 710 North Pleasant Street, Amherst, MA 01003 (United States)
Publication Date:
OSTI Identifier:
21565461
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal Letters
Additional Journal Information:
Journal Volume: 739; Journal Issue: 1; Other Information: DOI: 10.1088/2041-8205/739/1/L27; Journal ID: ISSN 2041-8205
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASYMMETRY; EVOLUTION; GALAXIES; HYDROGEN; RELAXATION TIME; ELEMENTS; NONMETALS

Citation Formats

Portas, Antonio, Scott, Tom C., Verdes-Montenegro, Lourdes, Sulentic, Jack, Sengupta, Chandreyee, Brinks, Elias, Heesen, Volker, Bosma, Albert, Athanassoula, E., Espada, Daniel, Verley, Simon, and Yun, Min. H I ASYMMETRIES IN THE ISOLATED GALAXY CIG 292. United States: N. p., 2011. Web. doi:10.1088/2041-8205/739/1/L27.
Portas, Antonio, Scott, Tom C., Verdes-Montenegro, Lourdes, Sulentic, Jack, Sengupta, Chandreyee, Brinks, Elias, Heesen, Volker, Bosma, Albert, Athanassoula, E., Espada, Daniel, Verley, Simon, & Yun, Min. H I ASYMMETRIES IN THE ISOLATED GALAXY CIG 292. United States. doi:10.1088/2041-8205/739/1/L27.
Portas, Antonio, Scott, Tom C., Verdes-Montenegro, Lourdes, Sulentic, Jack, Sengupta, Chandreyee, Brinks, Elias, Heesen, Volker, Bosma, Albert, Athanassoula, E., Espada, Daniel, Verley, Simon, and Yun, Min. Tue . "H I ASYMMETRIES IN THE ISOLATED GALAXY CIG 292". United States. doi:10.1088/2041-8205/739/1/L27.
@article{osti_21565461,
title = {H I ASYMMETRIES IN THE ISOLATED GALAXY CIG 292},
author = {Portas, Antonio and Scott, Tom C. and Verdes-Montenegro, Lourdes and Sulentic, Jack and Sengupta, Chandreyee and Brinks, Elias and Heesen, Volker and Bosma, Albert and Athanassoula, E. and Espada, Daniel and Verley, Simon and Yun, Min},
abstractNote = {We present Expanded Very Large Array (EVLA) D-array observations of the 21 cm line of neutral hydrogen (H I) of CIG 292, an isolated SA(s)b galaxy at a distance of {approx}24.3 Mpc. From previous H I single dish observations the galaxy was known to have a mildly asymmetric H I profile (A {sub flux} = 1.23 {+-} 0.3). Our EVLA observations show there is {approx}12% more H I projected south of the optical center (approaching velocities) than in the north (receding velocities), despite the H I extending {approx}16% further to the north than the south. The H I projected within the optical disk must have been perturbed within the H I relaxation time ({approx}10{sup 8} yr) which implies that this cannot have been caused by any of the three nearest companions, as their distance ({approx}0.5 Mpc) is too large. Neither H I-rich companions nor tidal tails were found within our field of view and velocity range covered. Our kinematical data suggest that the inner part harbors an oval distortion whereas the outer regions show signs of a modest warp. The mild asymmetry in the H I global profile thus actually masks stronger asymmetries in the two-dimensional distributions of gas and star-forming regions in this galaxy. Since the galaxy is isolated, this must predominantly be due to processes related to its formation and secular evolution.},
doi = {10.1088/2041-8205/739/1/L27},
journal = {Astrophysical Journal Letters},
issn = {2041-8205},
number = 1,
volume = 739,
place = {United States},
year = {2011},
month = {9}
}