TY - GEN
T1 - Extreme Carbon Overabundance in the 49 Ceti Circumstellar Gas
AU - Roberge, Aki
AU - Welsh, Barry
AU - Kamp, Inga
AU - Weinberger, Alycia J.
AU - Grady, Carol A.
PY - 2015/1
Y1 - 2015/1
N2 - We present analysis of C and O absorption in high-resolution HST-STIS
FUV spectra of the nearby A1V star 49 Ceti. This disk system is one of
the few showing the dust properties of a debris disk, but harboring
relatively abundant molecular gas more characteristic of a low-mass
protoplanetary disk. Since the disk is nearly edge-on, the line-of-sight
to the central star passes through the disk, permitting sensitive probes
of the circumstellar gas with absorption spectroscopy.Our FUV spectra
show many narrow circumstellar gas lines arising from several atomic
species, including neutral carbon (a gas not seen in the local ISM) and
neutral oxygen. We present an estimate of the total carbon column
density in the line-of-sight gas and limits on the oxygen column
density. Comparing the carbon abundance to a previous measurement of the
line-of-sight iron abundance, we see that the carbon is extremely
overabundant relative to the solar abundance. A similar overabundance is
seen in the Beta Pic disk gas, where the carbon brakes other gases from
being rapidly blown out by radiation pressure. The carbon in the 49 Cet
gas may play a similar role.
AB - We present analysis of C and O absorption in high-resolution HST-STIS
FUV spectra of the nearby A1V star 49 Ceti. This disk system is one of
the few showing the dust properties of a debris disk, but harboring
relatively abundant molecular gas more characteristic of a low-mass
protoplanetary disk. Since the disk is nearly edge-on, the line-of-sight
to the central star passes through the disk, permitting sensitive probes
of the circumstellar gas with absorption spectroscopy.Our FUV spectra
show many narrow circumstellar gas lines arising from several atomic
species, including neutral carbon (a gas not seen in the local ISM) and
neutral oxygen. We present an estimate of the total carbon column
density in the line-of-sight gas and limits on the oxygen column
density. Comparing the carbon abundance to a previous measurement of the
line-of-sight iron abundance, we see that the carbon is extremely
overabundant relative to the solar abundance. A similar overabundance is
seen in the Beta Pic disk gas, where the carbon brakes other gases from
being rapidly blown out by radiation pressure. The carbon in the 49 Cet
gas may play a similar role.
UR - http://adsabs.harvard.edu/abs/2015AAS...22531303R
M3 - Conference contribution
SP - 313.03
BT - American Astronomical Society Meeting Abstracts
ER -