GASP. II. A MUSE View of Extreme Ram-Pressure Stripping along the Line of Sight: Kinematics of the Jellyfish Galaxy JO201

Journal Article · Thu Jul 20 04:00:00 EDT 2017 · Astrophysical Journal

DOI:https://doi.org/10.3847/1538-4357/AA7875· OSTI ID:22876006

Bellhouse, C.; McGee, S. L. ^[1]; Jaffé, Y. L.; Hau, G. K. T. ^[2]; Poggianti, B. M.; Moretti, A.; Gullieuszik, M.; Bettoni, D.; Fasano, G.; D’Onofrio, M.; Omizzolo, A. ^[3]; Fritz, J. ^[4]; Sheen, Y. -K. ^[5]

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1. University of Birmingham School of Physics and Astronomy, Edgbaston, Birmingham (United Kingdom)
2. European Southern Observatory, Alonso de Cordova 3107, Vitacura, Casilla 19001, Santiago de Chile (Chile)
3. INAF—Astronomical Observatory of Padova, Vicolo dell’Osservatorio 5, I-35122 Padova (Italy)
4. Instituto de Radioastronomía y Astrofísica, Morelia (Mexico)
5. Korea Astronomy and Space Science Institute, 766, Daedeokdae-ro, Yuseong-gu, Daejeon, 34055 (Korea, Republic of)

This paper presents a spatially resolved kinematic study of the jellyfish galaxy JO201, one of the most spectacular cases of ram-pressure stripping (RPS) in the GAs Stripping Phenomena in galaxies with MUSE (GASP) survey. By studying the environment of JO201, we find that it is moving through the dense intracluster medium of Abell 85 at supersonic speeds along our line of sight, and that it is likely accompanied by a small group of galaxies. Given the density of the intracluster medium and the galaxy’s mass, projected position, and velocity within the cluster, we estimate that JO201 must so far have lost ∼50% of its gas during infall via RPS. The MUSE data indeed reveal a smooth stellar disk accompanied by large projected tails of ionized (Hα) gas, composed of kinematically cold (velocity dispersion <40 km s{sup −1}) star-forming knots and very warm (>100 km s{sup −1}) diffuse emission, that extend out to at least ∼50 kpc from the galaxy center. The ionized Hα-emitting gas in the disk rotates with the stars out to ∼6 kpc; but, in the disk outskirts, it becomes increasingly redshifted with respect to the (undisturbed) stellar disk. The observed disturbances are consistent with the presence of gas trailing behind the stellar component resulting from intense face-on RPS along the line of sight. Our kinematic analysis is consistent with the estimated fraction of lost gas and reveals that stripping of the disk happens outside-in, causing shock heating and gas compression in the stripped tails.

• OSTI ID: 22876006
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 844; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
DENSITY
DISPERSIONS
DISTURBANCES
EMISSION
GALACTIC EVOLUTION
GALAXIES
GALAXY CLUSTERS
MASS
RED SHIFT
SHOCK HEATING
SPECTROSCOPY
STARS
STRIPPING