Insights on bar quenching from a multi-wavelength analysis: The case of Messier 95. (arXiv:1812.04178v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+George_K/0/1/0/all/0/1">Koshy George</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Joseph_P/0/1/0/all/0/1">P. Joseph</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mondal_C/0/1/0/all/0/1">C. Mondal</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Subramanian_S/0/1/0/all/0/1">S. Subramanian</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Subramaniam_A/0/1/0/all/0/1">A. Subramaniam</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Paul_K/0/1/0/all/0/1">K. T. Paul</a>
The physical processes related to the effect of bar in the quenching of star
formation in the region between the nuclear/central sub-kpc region and the ends
of the bar (bar-region) of spiral galaxies is not fully understood. It is
hypothesized that the bar can either stabilize the gas against collapse,
inhibiting star formation or efficiently consume all the available gas, with no
fuel for further star formation. We present a multi-wavelength study using the
archival data of an early-type barred spiral galaxy, Messier 95, which shows
signatures of suppressed star formation in the bar-region. Using the optical,
ultraviolet, infrared, CO and HI imaging data we study the pattern of star
formation progression, stellar/gas distribution and try to provide insights on
the process responsible for the observed pattern. The FUV$-$NUV pixel colour
map reveals a cavity devoid of UV flux in the bar-region that interestingly
matches with the length of the bar ($sim$ 4.2kpc). The central nuclear region
of the galaxy is showing a blue color clump and along the major-axis of the
stellar bar the colour progressively becomes redder. Based on a comparison to
single stellar population models, we show that the region of galaxy along the
major-axis of the bar (unlike the region outside the bar) is comprised of
stellar populations with ages $geq$ 350 Myr, with a star-forming clump in the
center of younger ages ($sim$ 150Myr). Interestingly the bar-region is also
devoid of neutral and molecular hydrogen but with an abundant molecular
hydrogen present at the nuclear region of the galaxy. Our results are
consistent with a picture in which the stellar bar in Messier 95 is
redistributing the gas by funneling gas inflows to nuclear region, thus making
the bar-region devoid of fuel for star formation.
The physical processes related to the effect of bar in the quenching of star
formation in the region between the nuclear/central sub-kpc region and the ends
of the bar (bar-region) of spiral galaxies is not fully understood. It is
hypothesized that the bar can either stabilize the gas against collapse,
inhibiting star formation or efficiently consume all the available gas, with no
fuel for further star formation. We present a multi-wavelength study using the
archival data of an early-type barred spiral galaxy, Messier 95, which shows
signatures of suppressed star formation in the bar-region. Using the optical,
ultraviolet, infrared, CO and HI imaging data we study the pattern of star
formation progression, stellar/gas distribution and try to provide insights on
the process responsible for the observed pattern. The FUV$-$NUV pixel colour
map reveals a cavity devoid of UV flux in the bar-region that interestingly
matches with the length of the bar ($sim$ 4.2kpc). The central nuclear region
of the galaxy is showing a blue color clump and along the major-axis of the
stellar bar the colour progressively becomes redder. Based on a comparison to
single stellar population models, we show that the region of galaxy along the
major-axis of the bar (unlike the region outside the bar) is comprised of
stellar populations with ages $geq$ 350 Myr, with a star-forming clump in the
center of younger ages ($sim$ 150Myr). Interestingly the bar-region is also
devoid of neutral and molecular hydrogen but with an abundant molecular
hydrogen present at the nuclear region of the galaxy. Our results are
consistent with a picture in which the stellar bar in Messier 95 is
redistributing the gas by funneling gas inflows to nuclear region, thus making
the bar-region devoid of fuel for star formation.
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