PMOD 13.7m CO Observations toward SNRs G54.1+0.3 & G

22.7-0.2

2009.9.26-2009.11.04

Yang Su

Observations

• Date: 9.26-11.04, 5-7 hours/day (260 hours)

• Weather condition: 200-270 K• Ta r.m.s.~0.2-0.3 K/minute• 12CO/13CO/C18O: 0.37/0.11/0.11 km/s• Pointing: <3’’ for southern sky• Tracking: ~1-3’’• Main beam efficiency: 62%@90GHz

• FFTS:

• AOS:

• Aims:

a, To investigate the MC environment around SNRs; b, To study the association between SNRs and the ambient s

tar forming regions (e.g., HII regions; H2CO,H2O & CH3OH masers; Young stellar clusters);

• Method: a. Using 12CO/13CO/C18O (J=1-0) spectral and spatial inf

ormation to obtain the stable/unstable gas distribution and the kinematic velocity or distance of MCs;

b. Using HCO+(J=1-0)@89.18853GHz to identify the shock-MC regions;

c. Using HI 21cm & HISA to confine the source’s distance;d. Using Spitzer MIPS/IRAC IR data to study the emissions

of dust, PAH, molecular and atomic lines.

Background: SNR G54.1+0.3

Koo et al. 2008:

The AKARI 15um and Spitzer 5.8um emission enhancement (or the IR loop in the southwest of the remnant) indicate that the star formation triggered by some mechanism. Is it because of the Massive Progenitor’s Wind of the remnant?

Observations: We mapped the 3.5’*3.5’

area (r.m.s~0.2K) centered at the PSR position (the cross in the figures) with grid spacing 0.5’ (half beam). For the remnant area (2R~2’), the noise is less than 0.1K for the three CO lines.

Aims: Is there any 12CO

broadening or intensity distribution to show the shock interaction in the region of the IR loop?

Thick:12COThin:13CO*2Dashed: C18O*3

Focus on:A:[-10,0] km/sB:[0,6] km/sC:[7,12] km/sD:[17,28] km/sE:[49,57] km/s

Results: SNR G54.1+0.3

3’*3’ centered at PSR

No correlation

with SNRA

B C

D

E

• The 12CO distribution centered at the PSR position

• Upper-left:[1,4] km/s• Upper-right:[22,25] km/s• Lower-left:[52,55] km/s

B

E

D

• The 12-28 km/s MC wing (12CO)

Results: SNR G54.1+0.3

D

Red shift

Blue shift

• For 1-4 km/s MC, it seems surrounding the southwestern region of the remnant but no 12CO broadening;

• For [52,55] km/s MC, it located at the eastern and southern part of the remnant;

• For [22,24] km/s MC, the MC core covers the remnant but the 12CO broadening emission is ~1’ far from the radio boundary of the remnant.

• HISA analysis of MCs are needed because of d(SNR)>d(tangent point);

• HCO+ observations are needed in the regions of IR loop;

Conclusions: SNR G54.1+0.3

Strong 5.8um emission surrounding the remnant

Black Contours: C18O (71-82km/s)

White Contours: 1.4G Radio

HII A: RRL not to be detected

HII B: 71.2km/s; d~10.3kpc

HII C: 105-111km/s; d~7.4kpc

HII D: 70.9km/s; 4.4kpc

HII E: 74.1km/s; 4.6kpc

HII F: 74.8km/s; 4.6kpc

Masers (H2O,H2CO,CH3OH): 74.8km/s; 4.6 (4.26-4.97)kpc

Background: SNR G22.7-0.2

Aims 1:Are these star forming regions associated with the remnant?

HI A or MC AHI B or MC B

HII A

HII B

HII C

HII D

HII E

HII F

Masers

HI A: SNR bright Shell 1

HI B: SNR bright Shell 2

Observations: We mapped the

43’*35’ area (r.m.s~0.2K) centered at the geometric center of the remnant with grid spacing 2’. For the shell structure (or the IR bright regions), the noise is about 0.15K and grid spacing 1’.

Aims 2: Are there any MCs to

associate with the remnant? Note: the velocity we are interested in should be less than 85km/s.

MC AMC B

HII region F

Concave structure

12CO 68-70km/s+radio

The MC shellstructure alongthe radioperiphery &probably the 12CO broadening

1.4 GHz radio emission5.8um+13CO (74-80km/s) contours

13CO*5

• Given the good spatial correlation between the MC complex, the HII regions and the radio boundary of the remnant, we believe that all of them are probably physically contacted with SNR.

• The 77 km/s MC is likely associated with the remnant: 1,The MC A (east) is coincident well with the SNR’s radio shell;2,The MC B (center and south, N(H)>2E22cm-2) is likely corresp

onding to the darkness of the IR emission;3,The 12CO shell (v=68-70km/s; 13CO is weak) is surrounding th

e southeastern quarter of the remnant (in there IR 5.8um emission is strong);

• HI absorption for the remnant and HISA analysis for MCs suggest that the remnant is less than 5.1 kpc (85km/s) and probably at 4.7kpc (77km/s; the near side of the Scutum arm);

• The surrounding HII regions (D, E, & F) are likely associated with the remnant because of their similar distances. They were likely triggered by the massive progenitor’s wind of SNR;

• Very interesting is that, the eastern shell of the remnant displays prominent “concave structure”. And HII region F is just located ~2’ east of the SNR radio “concave structure”.

• HCO+ observations are needed in the regions of radio/IR peak;

Conclusions: SNR G22.7-0.2

Thanks