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 (10 7 -10 9 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. 1992 de Gregorio-Monsalvo, 2004

4. Hirahara et al. 1992 TMC-1 - 45m Nobeyama. - Southern part less evolved. - IRAS object supports it. Previous studies L1521E Hirota et al. 2002 - 45 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. 2003 - 70 m Goldstone - CCS depleted on the interior - NH 3 slightly depleted too. - More evolved stage Velusamy et al. 1995 B335 - 70m Goldstone + VLA D - Depletion at the center. - Contains a protostar. Lai et al. 2003 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 03301+3057) Hirano et al. 1997 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 1988. 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 10000 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