from gmc-snr interaction to gas-rich galaxy-galaxy merging
DESCRIPTION
From GMC-SNR interaction to gas-rich galaxy-galaxy merging. Yu GAO Purple Mountain Observatory, Nanjing, China Chinese Academy of Sciences . SFR vs. M(H2): No Unique Slope:1, 1.4, 1.7?. H2-dominated LIRGs/ULIRGs. HI ~ H2. HI-dominated LSB galaxies. - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: From GMC-SNR interaction to gas-rich galaxy-galaxy merging](https://reader036.vdocument.in/reader036/viewer/2022081520/568163ed550346895dd55ff7/html5/thumbnails/1.jpg)
From GMC-SNR interaction to gas-rich galaxy-galaxy merging
Yu GAOPurple Mountain Observatory, Nanjing, China
Chinese Academy of Sciences
![Page 2: From GMC-SNR interaction to gas-rich galaxy-galaxy merging](https://reader036.vdocument.in/reader036/viewer/2022081520/568163ed550346895dd55ff7/html5/thumbnails/2.jpg)
SFR vs. M(H2): No Unique Slope:1, 1.4, 1.7?
HI-dominatedLSB galaxies
HI ~ H2
H2-dom
inatedLIR
Gs/
ULIR
Gs
Gao & Solomon 2004b ApJExtragalactic SF=CO until 90’s
![Page 3: From GMC-SNR interaction to gas-rich galaxy-galaxy merging](https://reader036.vdocument.in/reader036/viewer/2022081520/568163ed550346895dd55ff7/html5/thumbnails/3.jpg)
Big
iel’s
talk
@S
FR50
SF thresholds maysimply reflect the change of the dominant cold gas phase in galaxiesfrom HI ->H2 & from H2->denseH2
Schruba+2011~linear in H2!
![Page 5: From GMC-SNR interaction to gas-rich galaxy-galaxy merging](https://reader036.vdocument.in/reader036/viewer/2022081520/568163ed550346895dd55ff7/html5/thumbnails/5.jpg)
Poster by Liu+
Liu & Gao 2011 arXiv:1106.2813
Dense H2 show the best correlation with SFR (linear Liu & Gao 2011).
![Page 6: From GMC-SNR interaction to gas-rich galaxy-galaxy merging](https://reader036.vdocument.in/reader036/viewer/2022081520/568163ed550346895dd55ff7/html5/thumbnails/6.jpg)
Bi-modal SF laws in high-z gals (Daddi+2010; Genzel+2010) also exist in local gals
![Page 7: From GMC-SNR interaction to gas-rich galaxy-galaxy merging](https://reader036.vdocument.in/reader036/viewer/2022081520/568163ed550346895dd55ff7/html5/thumbnails/7.jpg)
Introduction and Outline1. R=CO/13CO line intensity ratios: R ~2-5 Galactic Ring Survey 13CO (Jackson+06; Simon+01) UMass-StonyBrook CO survey (Sanders+86), ~5-10 Galactic center GMCs + normal spirals, ~10-20 Starbursts (eg, Aalto+1995) ~30-50 (U)LIRGs (few 13CO published; Papadopoulos+11)high R10 associated with small, warm but compact molecular clouds of low to
moderate optical depth, or the high [12CO/13CO] abundance ratio
2. Best case studies: Arp220 (Greve+09; Matsushita+09), NGC6240(Greve+09; U+11)
3. Resolved measurements in Antennae galaxies (Gao+01; Zhu+03), Taffy (Gao+03; Braine+03; Zhu+07); nearby gals. (Tan+11)
4. Supernova remnant (SNR) IC 443: GMC-SNR interactions (Wang+Scoville92; Zhang+10)
5. Implications: the molecular gas conditions in (U)LIRGs
![Page 8: From GMC-SNR interaction to gas-rich galaxy-galaxy merging](https://reader036.vdocument.in/reader036/viewer/2022081520/568163ed550346895dd55ff7/html5/thumbnails/8.jpg)
R~43
Greve+09
2. Best case studies
![Page 9: From GMC-SNR interaction to gas-rich galaxy-galaxy merging](https://reader036.vdocument.in/reader036/viewer/2022081520/568163ed550346895dd55ff7/html5/thumbnails/9.jpg)
Matsushita+09
![Page 10: From GMC-SNR interaction to gas-rich galaxy-galaxy merging](https://reader036.vdocument.in/reader036/viewer/2022081520/568163ed550346895dd55ff7/html5/thumbnails/10.jpg)
R~45
Greve+09
![Page 11: From GMC-SNR interaction to gas-rich galaxy-galaxy merging](https://reader036.vdocument.in/reader036/viewer/2022081520/568163ed550346895dd55ff7/html5/thumbnails/11.jpg)
BIMA+12m CO on HST image VLA 20cm on HST Very tight FIR-radio continuum correlation
3. Resolved measurements in ongoing mergers
![Page 12: From GMC-SNR interaction to gas-rich galaxy-galaxy merging](https://reader036.vdocument.in/reader036/viewer/2022081520/568163ed550346895dd55ff7/html5/thumbnails/12.jpg)
Gao+01, SFE (20cm/CO) contour map
![Page 13: From GMC-SNR interaction to gas-rich galaxy-galaxy merging](https://reader036.vdocument.in/reader036/viewer/2022081520/568163ed550346895dd55ff7/html5/thumbnails/13.jpg)
Zhu+03
R32~25R32~15
![Page 14: From GMC-SNR interaction to gas-rich galaxy-galaxy merging](https://reader036.vdocument.in/reader036/viewer/2022081520/568163ed550346895dd55ff7/html5/thumbnails/14.jpg)
Zhu+03
R21~20-30@overlap ~15@Nuclei
![Page 15: From GMC-SNR interaction to gas-rich galaxy-galaxy merging](https://reader036.vdocument.in/reader036/viewer/2022081520/568163ed550346895dd55ff7/html5/thumbnails/15.jpg)
Gao 2008
Zhang, Gao, Kong 2010 MNRAS
![Page 16: From GMC-SNR interaction to gas-rich galaxy-galaxy merging](https://reader036.vdocument.in/reader036/viewer/2022081520/568163ed550346895dd55ff7/html5/thumbnails/16.jpg)
SCUBA: Zhu, Gao, Seaquist & Dunne 2007 CO: Gao, Zhu, Seaquist 2003
450um contours on 8um image 850um contours on CO image
![Page 17: From GMC-SNR interaction to gas-rich galaxy-galaxy merging](https://reader036.vdocument.in/reader036/viewer/2022081520/568163ed550346895dd55ff7/html5/thumbnails/17.jpg)
R~15, 50 (The 12CO line intensities are divided by 10, Braine+03)
HII
![Page 18: From GMC-SNR interaction to gas-rich galaxy-galaxy merging](https://reader036.vdocument.in/reader036/viewer/2022081520/568163ed550346895dd55ff7/html5/thumbnails/18.jpg)
Tan+11 arXiv1103.5540
![Page 19: From GMC-SNR interaction to gas-rich galaxy-galaxy merging](https://reader036.vdocument.in/reader036/viewer/2022081520/568163ed550346895dd55ff7/html5/thumbnails/19.jpg)
Dame et al. 2001
Columnbia CO Survey
CO (1-0) in Gem OB1 GMC
Lee et al. 2008
1.4GHz Continuum
4. Supernova remnant (SNR) IC 443 -- the Jellyfish Nebula
![Page 20: From GMC-SNR interaction to gas-rich galaxy-galaxy merging](https://reader036.vdocument.in/reader036/viewer/2022081520/568163ed550346895dd55ff7/html5/thumbnails/20.jpg)
Simultaneous observations: 12CO,13CO & C18O (1-0)Typical Tsys~180-300K (rms noise ~0.2K in 0.4 km/s)Total obs. points >1000, total spectra~7000, 2Months Beam size and sampling grid: ~ 55” (~1’)
Gateway 2 Lhasa by sky train Array 3x3 + OTF 2011
![Page 21: From GMC-SNR interaction to gas-rich galaxy-galaxy merging](https://reader036.vdocument.in/reader036/viewer/2022081520/568163ed550346895dd55ff7/html5/thumbnails/21.jpg)
Zhang, Gao & Wang arXiv: 0911.4815
![Page 22: From GMC-SNR interaction to gas-rich galaxy-galaxy merging](https://reader036.vdocument.in/reader036/viewer/2022081520/568163ed550346895dd55ff7/html5/thumbnails/22.jpg)
Zhang, Gao & Wang arXiv: 0911.481570um and 160um overlaid with CO(1-0)
![Page 23: From GMC-SNR interaction to gas-rich galaxy-galaxy merging](https://reader036.vdocument.in/reader036/viewer/2022081520/568163ed550346895dd55ff7/html5/thumbnails/23.jpg)
Zhang, Gao & Wang arXiv: 0911.4815HI and radio continuum images overlaid with CO(1-0)
![Page 24: From GMC-SNR interaction to gas-rich galaxy-galaxy merging](https://reader036.vdocument.in/reader036/viewer/2022081520/568163ed550346895dd55ff7/html5/thumbnails/24.jpg)
CO/13CO Line Ratio & FIR Maps
[FeII], [SI], H2 0-0 S(0)
[OI] [CII] + Dust?
Spitzer 24 um
Spitzer 70 um
Spitzer 160 um
1. Line ratios are much higher in shocked regions than in the rest regions.
2. Line ratio maps in IC443 are strikingly well matched with the FIR images.
![Page 25: From GMC-SNR interaction to gas-rich galaxy-galaxy merging](https://reader036.vdocument.in/reader036/viewer/2022081520/568163ed550346895dd55ff7/html5/thumbnails/25.jpg)
SNR IC443
Yellow: 12CO
Blue: 13CO
Background:
Spitzer 24μm
Spectra Analysis
![Page 26: From GMC-SNR interaction to gas-rich galaxy-galaxy merging](https://reader036.vdocument.in/reader036/viewer/2022081520/568163ed550346895dd55ff7/html5/thumbnails/26.jpg)
![Page 27: From GMC-SNR interaction to gas-rich galaxy-galaxy merging](https://reader036.vdocument.in/reader036/viewer/2022081520/568163ed550346895dd55ff7/html5/thumbnails/27.jpg)
5. Implications to (U)LIRGs• Concentrated molecular gas of ~10^10Msun in ~1kpc
(vs. >10 kpc 10^9 Msun H2 in the Galaxy) (~10^3)• Packed with dense cores (HCN-FIR) and even intercloud
(or inter-dense-core) medium is highly molecular• SNe rates in ULIRGs ~100 times that of the Milky Way• Most dense cores are shocked by SNRs in ULIRGs
(~10^5xMW) besides strong galaxy-galaxy collisions• Highly shocked regions higher R=CO/13CO in LIRGs• The abnormally high ratios of R (& CO/C18O) found in
SNR IC443 of shock-origin are comparable to the observed values in starbursts and (U)LIRGs, likely implying their same physical origin. Gao & Solomon 04, Gao+07: Dense H2 Dense Cores