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High Resolution Observations in B1-IRS: ammonia, CCS and water masers Claire Chandler, NRAO José F. Gómez, LAEFF-INTA Thomas B. Kuiper, JPL José M. Torrelles,

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Presentation on theme: "High Resolution Observations in B1-IRS: ammonia, CCS and water masers Claire Chandler, NRAO José F. Gómez, LAEFF-INTA Thomas B. Kuiper, JPL José M. Torrelles,"— Presentation transcript:

1 High Resolution Observations in B1-IRS: ammonia, CCS and water masers Claire Chandler, NRAO José F. Gómez, LAEFF-INTA Thomas B. Kuiper, JPL José M. Torrelles, CSIC-IEEC Guillem Anglada, CSIC-IAA Itziar de Gregorio-Monsalvo LAEFF-INTA (Spain)

2 Molecular lines provide information about T, density and kinematics. Quiescent medium: C 3 H 2, N 2 H +, H 13 CO +, DCO +, CCS, NH 3 … Shocked regions: SiO, CH 3 OH, H 2 CO, HCN, CN, SO, SO 2,H 2 O… Spatial distribution of some molecules in star forming regions depends on: - Physical conditions - Chemistry (time-dependent) They can be use as a ‘clock’ to date the age of a dense core. Transparency of dust surrounding YSO’s at centimeter wavelengths. Specially interesting: (NH 3, H 2 O and CCS) - NH 3 (1,1) High density gas tracer - H 2 O masers : High density ( cm -3 ) and warm gas (T K ~100K) - CCS Not very opaque, intense and abundant in protostellar cores Has no splitting in hyperfine structure High density gas tracer Why study molecular lines?

3 Anticorrelation between CCS and ammonia (Suzuki et al, 1992). Single dish observations, starless cores. Evolution effect CCS intense in cold and quiescent cores Star formation desorption of ammonia. [CCS] / [NH 3 ] indicator of cloud evolution Suzuki et al de Gregorio-Monsalvo, 2004

4 Hirahara et al TMC m Nobeyama. - Southern part less evolved. - IRAS object supports it. Previous studies L1521E Hirota et al m Nobeyama - Quiescent starless core - No outflows or submm emission or infalling. - CCS not depleted - NH 3 emission very faint. - Very early stage. de Gregorio-Monsalvo, 2004

5 B68 Lai et al m Goldstone - CCS depleted on the interior - NH 3 slightly depleted too. - More evolved stage Velusamy et al B m Goldstone + VLA D - Depletion at the center. - Contains a protostar. Lai et al de Gregorio-Monsalvo, 2004

6 B1 molecular cloud in Perseus (350 pc; Bachiller et al. 1990). Class 0 source (Hurt et al. 1996). SiO emission (Yamamoto et al. 1992) and CO (1-0) outflow (Hirano et al. 1997). Water maser emission (Furuya et al. 2001). CCS observations at 33.8 GHz with BIMA (Lai et al. 2000). B1-IRS (IRAS ) Hirano et al Lai et al. 2000

7 Goals: - Study dynamics and evolution at high resolution. - Test CCS vs NH 3 in star forming regions at high resolution. Observations (VLA-D configuration): - Simultaneous observations of CCS (22.35 GHz) and H 2 O (22.24 GHz). - 4 IF spectral line mode. Archive data (VLA-D configuration): - Ammonia (23.69 GHz) from VLA Observations de Gregorio-Monsalvo, 2004

8 H 2 O masers and 2MASS image - 2MASS point source at the tip of the CO outflow. - masers located at 1” in an elongated structure. - H 2 O masers located at 1” in an elongated structure. - Unbound motions, probably tracing a jet (Torrelles et al. 1997). - Lack of velocity gradient ( Outflow lies nearer the plane of the sky ? ). Hirano et al, 1997

9 H 2 O masers and 2MASS image - 2MASS point source at the tip of the CO outflow. - masers located at 1” in an elongated structure. - H 2 O masers located at 1” in an elongated structure. - Unbound motions, probably tracing a jet (Torrelles et al. 1997). - Lack of velocity gradient ( Outflow lies nearer the plane of the sky ? ).

10 H 2 O masers and 2MASS image April 2003October 1998February 1999 Multiepoch water masers  (‘’)  (‘’)

11 H 2 O masers and 2MASS image Outflow configuration compatible with our observations:

12 CCS resulting map: - CCS emission is clumpy. - Redshifted clumps. - Velocity gradient blue-shifted towards the central source towards the central source - Bound motions. - Strong interaction between CCS clumps and the outflow. clumps and the outflow. - Compatible with infalling models AU at 350 pc de Gregorio-Monsalvo, 2004

13 CCS resulting map:

14 Plane of the sky

15 Ammonia map: - Extended emission. - Peaks near the center of the source and in the S-E. the source and in the S-E. - Dynamics compatible with CCS velocity field. CCS velocity field. de Gregorio-Monsalvo, 2004

16 Ammonia versus CCS …………Anticorrelation!!! de Gregorio-Monsalvo, 2004

17 Conclusions Conclusions: CCS + NH 3 + water maser Dynamics, evolution stage of B1-IRS CCS + NH 3 + water maser Dynamics, evolution stage of B1-IRS Reflection nebula elongated in the same direction of the outflow: Reflection nebula elongated in the same direction of the outflow: CO Outflow near the plane of the sky (2MASS position). CO Outflow near the plane of the sky (2MASS position). Water masers trace a jet. Water masers trace a jet. CCS emission is clumpy and redshifted. CCS emission is clumpy and redshifted. Gradient in velocity suggest a strong interaction between the CCS and Gradient in velocity suggest a strong interaction between the CCS and the outflow. the outflow. Dynamics compatible with infalling models. Dynamics compatible with infalling models. CCS / NH 3 anticorrelation at small scales and in star forming regions. CCS / NH 3 anticorrelation at small scales and in star forming regions. de Gregorio-Monsalvo, 2004

18 Futurework Future work: Combination with single dish data to avoid the missing Combination with single dish data to avoid the missing short spacings in the VLA data: short spacings in the VLA data: - CCS and NH 3 maps with DSN 70 m (Madrid). - CCS and NH 3 maps with DSN 70 m (Madrid). NH 3 VLA observation in D-configuration: NH 3 VLA observation in D-configuration: - More integration time. - New receivers. H 2 O masers VLA observation in A-configuration or H 2 O masers VLA observation in A-configuration or VLBA : VLBA : - Better precision in position. - Dynamical Structure of the jet. VLA observation in D-configuration: VLA observation in D-configuration: - New CCS + H 2 O maser emission detected with DSN 70 m. - New regions with CCS + H 2 O maser emission detected with DSN 70 m. de Gregorio-Monsalvo, 2004


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