Tracing Ram-Pressure Stripping with Warm Molecular Hydrogen Emission
S. Sivanandam, M. Rieke, und G. Rieke. (2014)cite arxiv:1410.0688Comment: 26 pages, 22 figures, accepted for publication in ApJ.
Zusammenfassung
We use the Spitzer Infrared Spectrograph (IRS) to study four infalling
cluster galaxies with signatures of on-going ram-pressure stripping. H$_2$
emission is detected in all four; two show extraplanar H$_2$ emission. The
emission usually has a warm (T $\sim$ $115 - 160$K) and a hot (T $\sim$ 400 $-$
600K) component that is approximately two orders of magnitude less massive than
the warm one. The warm component column densities are typically $10^19 -
10^20$ cm$^-2$ with masses of $10^6 - 10^8 M_ødot$. The warm H$_2$ is
anomalously bright compared with normal star-forming galaxies and therefore may
be excited by ram-pressure. In the case of CGCG 97-073, the H$_2$ is offset
from the majority of star formation along the direction of the galaxy's motion
in the cluster, suggesting it is forming in the ram-pressure wake of the
galaxy. Another galaxy, NGC 4522, exhibits a warm H$_2$ tail approximately 4
kpc in length. These results support the hypothesis that H$_2$ within these
galaxies is shock-heated from the interaction with the intracluster medium.
Stripping of dust is also a common feature of the galaxies. For NGC 4522, where
the distribution of dust at 8 $\mu$m is well resolved, knots and ripples
demonstrate the turbulent nature of the stripping process. The H$\alpha$ and 24
$\mu$m luminosities show that most of the galaxies have star formation rates
comparable to similar mass counterparts in the field. Finally, we suggest a
possible evolutionary sequence primarily related to the strength of
ram-pressure a galaxy experiences to explain the varied results observed in our
sample.
Beschreibung
[1410.0688] Tracing Ram-Pressure Stripping with Warm Molecular Hydrogen Emission
%0 Generic
%1 sivanandam2014tracing
%A Sivanandam, Suresh
%A Rieke, Marcia J.
%A Rieke, George H.
%D 2014
%K molecular pressure ram shocks stripping warm
%T Tracing Ram-Pressure Stripping with Warm Molecular Hydrogen Emission
%U http://arxiv.org/abs/1410.0688
%X We use the Spitzer Infrared Spectrograph (IRS) to study four infalling
cluster galaxies with signatures of on-going ram-pressure stripping. H$_2$
emission is detected in all four; two show extraplanar H$_2$ emission. The
emission usually has a warm (T $\sim$ $115 - 160$K) and a hot (T $\sim$ 400 $-$
600K) component that is approximately two orders of magnitude less massive than
the warm one. The warm component column densities are typically $10^19 -
10^20$ cm$^-2$ with masses of $10^6 - 10^8 M_ødot$. The warm H$_2$ is
anomalously bright compared with normal star-forming galaxies and therefore may
be excited by ram-pressure. In the case of CGCG 97-073, the H$_2$ is offset
from the majority of star formation along the direction of the galaxy's motion
in the cluster, suggesting it is forming in the ram-pressure wake of the
galaxy. Another galaxy, NGC 4522, exhibits a warm H$_2$ tail approximately 4
kpc in length. These results support the hypothesis that H$_2$ within these
galaxies is shock-heated from the interaction with the intracluster medium.
Stripping of dust is also a common feature of the galaxies. For NGC 4522, where
the distribution of dust at 8 $\mu$m is well resolved, knots and ripples
demonstrate the turbulent nature of the stripping process. The H$\alpha$ and 24
$\mu$m luminosities show that most of the galaxies have star formation rates
comparable to similar mass counterparts in the field. Finally, we suggest a
possible evolutionary sequence primarily related to the strength of
ram-pressure a galaxy experiences to explain the varied results observed in our
sample.
@misc{sivanandam2014tracing,
abstract = {We use the Spitzer Infrared Spectrograph (IRS) to study four infalling
cluster galaxies with signatures of on-going ram-pressure stripping. H$_2$
emission is detected in all four; two show extraplanar H$_2$ emission. The
emission usually has a warm (T $\sim$ $115 - 160$K) and a hot (T $\sim$ 400 $-$
600K) component that is approximately two orders of magnitude less massive than
the warm one. The warm component column densities are typically $10^{19} -
10^{20}$ cm$^{-2}$ with masses of $10^6 - 10^8 M_\odot$. The warm H$_2$ is
anomalously bright compared with normal star-forming galaxies and therefore may
be excited by ram-pressure. In the case of CGCG 97-073, the H$_2$ is offset
from the majority of star formation along the direction of the galaxy's motion
in the cluster, suggesting it is forming in the ram-pressure wake of the
galaxy. Another galaxy, NGC 4522, exhibits a warm H$_2$ tail approximately 4
kpc in length. These results support the hypothesis that H$_2$ within these
galaxies is shock-heated from the interaction with the intracluster medium.
Stripping of dust is also a common feature of the galaxies. For NGC 4522, where
the distribution of dust at 8 $\mu$m is well resolved, knots and ripples
demonstrate the turbulent nature of the stripping process. The H$\alpha$ and 24
$\mu$m luminosities show that most of the galaxies have star formation rates
comparable to similar mass counterparts in the field. Finally, we suggest a
possible evolutionary sequence primarily related to the strength of
ram-pressure a galaxy experiences to explain the varied results observed in our
sample.},
added-at = {2014-10-06T09:40:15.000+0200},
author = {Sivanandam, Suresh and Rieke, Marcia J. and Rieke, George H.},
biburl = {https://www.bibsonomy.org/bibtex/22e2a61ddc2f9e0a952ad056f581c274b/miki},
description = {[1410.0688] Tracing Ram-Pressure Stripping with Warm Molecular Hydrogen Emission},
interhash = {65e14af278fdfc93b3c3914d4236b390},
intrahash = {2e2a61ddc2f9e0a952ad056f581c274b},
keywords = {molecular pressure ram shocks stripping warm},
note = {cite arxiv:1410.0688Comment: 26 pages, 22 figures, accepted for publication in ApJ},
timestamp = {2014-10-06T09:40:15.000+0200},
title = {Tracing Ram-Pressure Stripping with Warm Molecular Hydrogen Emission},
url = {http://arxiv.org/abs/1410.0688},
year = 2014
}