Physical conditions & chemistry
- Astrochemistry as a diagnostic...
- 50+ molecules detected exgalactically
- CO n>10^2, HCN n>10^4
- temperature NH3, H2CO
- Only works if molecules excited by collisions
- 12CO/13CO increases towards GC because more diffuse gas [my q: integrated?]
- "Raisin Roll" view:
- Mol massin dense clumps, HI diffuse throughout
- HCO+, H3O+, HNC, HC3N, CN, SiO, H2O
- General Trends
- HNC 1-0 anticorrelated with HCN+ 1-0
- C2H ubiquitous
- "Hot Cores"
- Arp 220
- Drive outflows
- "Boring" NGC 1377 (optically) + has very deep SiO absorption + molecular outflow M~10^7 Msun + 860um optically thick core
- NGC 4418 "Ugly Duckling" galaxy + optically thick "atmosphere" dust core surrounded by molecular disk + N~10^25 cm^-2 + inner temp ~200-300K + molecular "disk" ~50K
- unclear how common optically thick cores are + can be studied with vibrationally excited molecules
- NGC 4418 + Global spectrum dominated by vibrationally excited HC3N
- Mrk231 + HCN outflow, 1000 km/s + vibrationally excited HCN in core
- vibrationally excited lines trace warped disk
- Arp 220W: amplified IR-pumped HNC
- ALMA NGC 4418 "spectral scan"
- dominated by vibrational lines
- SMA spectral scanning in Arp 220
- problematic: wide lines
- vibrational lines are the new standard
- Less obscured galaxies
- NGC 253, IC 342, Maffei 2, NGC 1068...
- same chemistry can trace outflows or star formation
- HNC, HCN, HCO+ correlated with 3mm continuum: trace SF
- HNCO, CH3OH, SiO anti-correlated with SF: probably trace outflows
- N2H+ - "warm gas" and "warm dust". Not the same in our galaxy & others
- NGC 1068
- PdBI Spirals around center
- ALMA bar + spirals + central cirumnuclear disk
- complicated chemistry towards true center
- noncircular motions
- More results:
- ALMA + ATCA towards Cen A
- NGC 1097
- HC3N in Mrk 231
- HCN in wind... extreme hcn abundance
Questions:
- Inner NGC 1068 ring - what resolution can you get with ALMA? Can you see kinematics?
- A: Yes, can see kinematics. 0.1", can do ~10x better eventually. 400 km/s
- Draw attention to MOPRA MALT-90: good comparison survey for galaxies
- Thanks