Tunnard, RCA;
Greve, TR;
Garcia-Burillo, S;
Graciá Carpio, J;
Fischer, J;
Fuente, A;
González-Alfonso, E;
... Planesas, P; + view all
(2015)
Chemically Distinct Nuclei and Outflowing Shocked Molecular Gas in Arp 220.
The Astrophysical Journal: an international review of astronomy and astronomical physics
![[thumbnail of Tunnard OutflowDetection-rcat-refereed1.pdf]](https://discovery.ucl.ac.uk/style/images/fileicons/application_pdf.png) |
PDF
Tunnard OutflowDetection-rcat-refereed1.pdf Available under License : See the attached licence file. Download (7MB) |
Abstract
We present the results of interferometric spectral line observations of Arp 220 at 3.5mm and 1.2mm from the Plateau de Bure Interferometer (PdBI), imaging the two nuclear disks in H13CN(1−0) and (3−2), H13CO+(1−0) and (3−2), and HN13C(3−2) as well as SiO(2−1) and (6−5), HC15N(3−2), and SO(66−55). The gas traced by SiO(6−5) has a complex and extended kinematic signature including a prominent P Cygni profile, almost identical to previous observations of HCO+(3−2). Spatial offsets 0.1″ north and south of the continuum centre in the emission and absorption of the SiO(6−5) P Cygni profile in the western nucleus (WN) imply a bipolar outflow, delineating the northern and southern edges of its disk and suggesting a disk radius of ∼40 pc, consistent with that found by ALMA observations of Arp 220. We address the blending of SiO(6−5) and H13CO+(3−2) by considering two limiting cases with regards to the H13CO+ emission throughout our analysis. Large velocity gradient (LVG) modelling is used to constrain the physical conditions of the gas and to infer abundance ratios in the two nuclei. Our most conservative lower limit on the [H13CN]/[H13CO+] abundance ratio is 11 in the WN, cf. 0.10 in the eastern nucleus (EN). Comparing these ratios to the literature we argue on chemical grounds for an energetically significant AGN in the WN driving either X-ray or shock chemistry, and a dominant starburst in the EN.
| Type: | Article |
|---|---|
| Title: | Chemically Distinct Nuclei and Outflowing Shocked Molecular Gas in Arp 220 |
| Open access status: | An open access version is available from UCL Discovery |
| Language: | English |
| Keywords: | submillimeter: general, galaxies: jets, galaxies: individual(Arp 220), galaxies: active, galaxies: ISM |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1458882 |
Archive Staff Only
 |
View Item |
