1. The SMA CO(6-5) & 690 GHz Continuum Observations of Arp 220 Satoki Matsushita (ASIAA) D. Iono (CfA), C.-Y. Chou (ASIAA), M. Gurwell (CfA), P.-Y. Hsieh (NTU, ASIAA), T. Hunter(CfA), J. Lim (ASIAA), P.-Y. Hsieh (NTU, ASIAA), T. Hunter(CfA), J. Lim (ASIAA), S. Muller (ASIAA), A.B. Peck (CfA), G. Petitpas (CfA), K. Sakamoto (NAOJ, CfA), S. Sawada-Satoh (ASIAA), Dinh-V-Trung (ASIAA), M.C. Wiedner (Univ. Koln, CfA), D. Wilner (CfA)

2. Introduction Arp 220 Arp 220 Prototypical Ultra Luminous Infrared Galaxy (ULIRG). Prototypical Ultra Luminous Infrared Galaxy (ULIRG). One of the nearest ULIRGs (77 Mpc) One of the nearest ULIRGs (77 Mpc) L 8-1000  m = 1.4 x 10 12 L sun (Soifer et al. 1987) L 8-1000  m = 1.4 x 10 12 L sun (Soifer et al. 1987) Final stage of galaxy merger. Final stage of galaxy merger. Two nuclei at the center (~1” / 370 pc separation). Two nuclei at the center (~1” / 370 pc separation). High resolution high-J CO lines & dust imagings are important to know about the conditions of extreme starburst in merging sequence. High resolution high-J CO lines & dust imagings are important to know about the conditions of extreme starburst in merging sequence. ULIRGs are believe to be nearby counterparts for high-z starburst galaxies. ULIRGs are believe to be nearby counterparts for high-z starburst galaxies. Due to the redshift, many of the high-z galaxies observed with high-J CO lines. Due to the redshift, many of the high-z galaxies observed with high-J CO lines. Observing high-J CO lines of nearby ULIRGs are important for the study of high-z starburst galaxies. Observing high-J CO lines of nearby ULIRGs are important for the study of high-z starburst galaxies. 2.8’ 2.2’ Arp 1966 Palomar 5m Scoville et al. 1998 HST/NICMOS 19”

3. Observation & Calibration Telescope: SMA Telescope: SMA Antennas: 1,2,3,4,5,6 Antennas: 1,2,3,4,5,6 Date: March 2 nd, 2005 Date: March 2 nd, 2005 225 GHz opacity = 0.03-0.04 225 GHz opacity = 0.03-0.04 Frequency Setting Frequency Setting LSB: 679.2 GHz CO(6-5) LSB: 679.2 GHz CO(6-5) USB: 689.2 GHz Continuum USB: 689.2 GHz Continuum Calibrators Calibrators Amplitude & Phase: Callisto (~50 o away) Amplitude & Phase: Callisto (~50 o away) Flux of Ceres shows 78% of the actual. => Flux accuracy ~ 20%-25% Flux of Ceres shows 78% of the actual. => Flux accuracy ~ 20%-25% Position of Arp 220 shifted for ~0.7”, consistent with the baseline errors. Position of Arp 220 shifted for ~0.7”, consistent with the baseline errors. Bandpass: Mars, Callisto, & Ganymede Bandpass: Mars, Callisto, & Ganymede Imaging Imaging Beam size: 1.2” x 0.8” (450 pc x 300 pc) Beam size: 1.2” x 0.8” (450 pc x 300 pc)

4. Results Arp 220 689 GHz (435  m) continuum Arp 220 689 GHz (435  m) continuum Total flux: 2.3 Jy Total flux: 2.3 Jy Single-dish 450  m Single-dish 450  m UKIRT UKT14 UKIRT UKT14 Eales et al. 1989 Eales et al. 1989 3.0+-1.1 Jy 3.0+-1.1 Jy Missing flux = 23% Missing flux = 23% JCMT SCUBA JCMT SCUBA Dunne & Eales 2001 Dunne & Eales 2001 6.3+-0.8 Jy 6.3+-0.8 Jy Missing flux = 63% Missing flux = 63% Contours: -2, 2, 4, 6  1.2” x 0.8”

5. Results Comparison between other continuum images in different wavelengths. Comparison between other continuum images in different wavelengths. W Nucleus 0.96 Jy/beam E Nucleus 0.90 Jy/beam Sakamoto et al. 1.2” x 0.8” Sakamoto et al. (1999)

6. Discussion (Continuum) Arp 220 689 GHz continuum Arp 220 689 GHz continuum East Nucleus: 900 +- 0.16 mJy/B East Nucleus: 900 +- 0.16 mJy/B West Nucleus: 960 +- 0.16 mJy/B West Nucleus: 960 +- 0.16 mJy/B E/W flux ratio: 0.94 +- 0.23 E/W flux ratio: 0.94 +- 0.23 Arp 220 230 GHz continuum (Sakamoto et al. 1999) Arp 220 230 GHz continuum (Sakamoto et al. 1999) East Nucleus: 66 +- 9.3 mJy/B East Nucleus: 66 +- 9.3 mJy/B West Nucleus: 142 +- 9.3 mJy/B West Nucleus: 142 +- 9.3 mJy/B E/W flux ratio: 0.46 +- 0.07 E/W flux ratio: 0.46 +- 0.07 Arp 220

7. Comparison of SED with that of the high-z QSO BR1202-0725 Comparison of SED with that of the high-z QSO BR1202-0725 Discussion (Continuum) Arp 220 Blue: Total flux Red: W Nucleus Green: E Nucleus 3.2 3.2 1.8 1.8 .9 .9 D. Iono et al., poster in this meeting. .5 .5 .4 .4 SMA 333 GHz (900  m) image BR1202-0725 The two nuclei/sources in both galaxies seem to have different spectral indices. The two nuclei/sources in both galaxies seem to have different spectral indices. Different dust properties? Different dust properties? Effect of synchrotron / free-free emission? Effect of synchrotron / free-free emission? Note that separations of the nuclei are very different: Note that separations of the nuclei are very different: Arp 220: ~ 300-400 pc vs BR 1202-0725: ~ 30-40 kpc Arp 220: ~ 300-400 pc vs BR 1202-0725: ~ 30-40 kpc Note that BR1202-0725 is z ~ 4.7 => 350 GHz -> 2 THz Note that BR1202-0725 is z ~ 4.7 => 350 GHz -> 2 THz

8. Results Arp 220 CO(6-5) Integrated Intensity Arp 220 CO(6-5) Integrated Intensity 1.2” x 0.8” Sakamoto et al. Sakamoto et al. (1999)

9. Results Arp 220 CO(6-5) Velocity Map Arp 220 CO(6-5) Velocity Map SMA CO(6-5) Sakamoto et al. 1999

10. Results ARP 220 CO(6-5) Spectra ARP 220 CO(6-5) Spectra Peak Temperature @ 1.2” x 0.8” beam Peak Temperature @ 1.2” x 0.8” beam E Nucleus: Peak = 9.4 K E Nucleus: Peak = 9.4 K W Nucleus: Peak = 10.6 K W Nucleus: Peak = 10.6 K Peak Temperature assuming 0.57” x 0.52” size Peak Temperature assuming 0.57” x 0.52” size E Nucleus: Peak = 30 K E Nucleus: Peak = 30 K W Nucleus: Peak = 34 K W Nucleus: Peak = 34 K ARP 220 CO(2-1) ARP 220 CO(2-1) Peak Temperature @ 0.57” x 0.52” size Peak Temperature @ 0.57” x 0.52” size E Nucleus: Peak = 38 K E Nucleus: Peak = 38 K W Nucleus: Peak = 37 K W Nucleus: Peak = 37 K 8.3 K 5.6 K 8.3 K 5.6 K E Nucleus W Nucleus 0.0 K 5350 km/s

11. Discussion (CO lines) Comparison of CO intensities between nearby to high-z galaxies Comparison of CO intensities between nearby to high-z galaxies Arp 220 Kawabe et al. 1999 Arp 220 CO intensities are similar to nearby starburst & high-z starburst galaxy. Arp 220 CO intensities are similar to nearby starburst & high-z starburst galaxy.

12. Conclusion We succeeded to image CO(6-5) & 690 GHz (435  m) continuum maps of Arp 220 with the SMA. We succeeded to image CO(6-5) & 690 GHz (435  m) continuum maps of Arp 220 with the SMA. 690 GHz continuum image 690 GHz continuum image Two nuclei seems to have different spectral indices at sub-mm. Two nuclei seems to have different spectral indices at sub-mm. CO(6-5) image CO(6-5) image CO(6-5) emission seems to have similar distribution & kinematics to that of CO(2-1). CO(6-5) emission seems to have similar distribution & kinematics to that of CO(2-1). Physical conditions of CO gas seems to have similar to that of nearby & high-z starbursts. => Support the idea that ULIRGs are the nearby counter part of high-z starburst galaxies. Physical conditions of CO gas seems to have similar to that of nearby & high-z starbursts. => Support the idea that ULIRGs are the nearby counter part of high-z starburst galaxies.