1. H i in group interactions: HCG 44
- Author
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Claude Carignan, Sahba Yahya, Paolo Serra, D. M. Lucero, S. S. Passmoor, Lukas Leisman, Michelle E. Cluver, Kelley M. Hess, Department of Astronomy, Faculty of Science, and Astronomy
- Subjects
History ,TIDAL DEBRIS ,FAST ALPHA SURVEY ,Density ,Astrophysics ,01 natural sciences ,Example ,law.invention ,Synthesis ,Group (periodic table) ,law ,histoire ,Galaxy group ,galaxies: interactions ,Radio telescopes ,010303 astronomy & astrophysics ,Observations ,Physics ,Ecology ,galaxies: groups: individual: HCG 44 ,Astrophysics::Instrumentation and Methods for Astrophysics ,Atomic hydrogen ,COLD GAS ,environnement ,ATOMIC GAS ,HICKSON COMPACT-GROUPS ,Order ,Astrophysics - Instrumentation and Methods for Astrophysics ,galaxies: evolution ,environment ,galaxies: ISM ,colonne ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,STAR-FORMATION ,Radio telescope ,Telescope ,0103 physical sciences ,survey ,GALAXY GROUPS ,Nature and nurture ,prospection ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,Astrophysics::Galaxy Astrophysics ,radio lines: galaxies ,CLUSTER GALAXIES ,010308 nuclear & particles physics ,Star formation ,Order (ring theory) ,Astronomy ,Astronomy and Astrophysics ,Astrophysics - Astrophysics of Galaxies ,NEUTRAL HYDROGEN ,jeNne ,Compact group ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Adaptation (Biology) ,SKY SURVEY ,Euthenics ,Telescopes - Abstract
Extending deep observations of the neutral atomic hydrogen (HI) to the environment around galaxy groups can reveal a complex history of group interactions which is invisible to studies that focus on the stellar component. Hickson Compact Group 44 (HCG 44) is a nearby example and we have combined HI data from the Karoo Array Telescope, Westerbork Synthesis Radio Telescope, and Arecibo Legacy Fast ALFA survey, in order to achieve high column density sensitivity (N_HI < 2x10^18 cm^-2) to the neutral gas over a large field-of-view beyond the compact group itself. We find the giant HI tail north of HCG 44 contains 1.1x10^9 M_Sun of gas and extends 450 kpc from the compact group: twice as much mass and 33% further than previously detected. However, the additional gas is still unable to account for the known HI deficiency of HCG 44. The tail likely formed through a strong tidal interaction and HI clouds in the tail have survived for 1 Gyr or more after being stripped. This has important implications for understanding the survival of neutral clouds in the intragroup and circumgroup medium, and we discuss their survival in the context of simulations of cold gas in hot halos. HCG 44 is one of a growing number of galaxy groups found to have more extended HI in the intragroup and circumgroup medium than previously measured. Our results provide constraints for simulations on the properties of galaxy group halos, and reveal a glimpse of what will be seen by future powerful HI telescopes and surveys., 12 pages, 6 figures. Accepted for publication in MNRAS
- Published
- 2016
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