High Resolution Observations in B1-IRS: ammonia , CCS and water masers

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

2. Why study molecular lines? • • Molecular lines provide information about T, density and kinematics. • Quiescent medium: C3H2, N2H+, H13CO+, DCO+, CCS, NH3 … • Shocked regions: SiO, CH3OH, H2CO, HCN, CN, SO, SO2,H2O… • • 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: (NH3, H2O and CCS) • - NH3 (1,1) High density gas tracer • - H2O masers : High density (107-109cm-3) and warm gas (TK~100K) • - CCS Not very opaque, intense and abundant in protostellar cores • Has no splitting in hyperfine structure • High density gas tracer

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] / [NH3] indicator of cloud evolution Suzuki et al. 1992 de Gregorio-Monsalvo, 2004

4. Previous studies TMC-1 -45m Nobeyama. - Southern part less evolved. - IRAS object supports it. Hirahara et al. 1992 L1521E • CCS not depleted • NH3 emission • very faint. • - Very early stage. • -45 m Nobeyama • Quiescent starless core • No outflows or submm • emission or infalling. Hirota et al. 2002 de Gregorio-Monsalvo, 2004

5. B68 • - 70 m Goldstone • CCS depleted on the interior • NH3 slightly depleted too. • More evolved stage Lai et al. 2003 B335 • -70m Goldstone + VLA D • Depletion at the center . • - Contains a protostar. Lai et al. 2003 Velusamy et al. 1995 de Gregorio-Monsalvo, 2004

6. B1-IRS (IRAS 03301+3057) • 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). Lai et al. 2000 Hirano et al. 1997

7. VLA Observations • Goals: - Study dynamics and evolution at high resolution. - Test CCS vs NH3 in star forming regions at high resolution. • Observations (VLA-D configuration): - Simultaneous observations of CCS (22.35 GHz) and H2O (22.24 GHz). - 4 IF spectral line mode. • Archive data (VLA-D configuration): - Ammonia (23.69 GHz) from1988. de Gregorio-Monsalvo, 2004

8. H2O masers and 2MASS image Hirano et al, 1997 • 2MASS point source at the tip of the CO outflow. • - H2O 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 ? ).

9. H2O masers and 2MASS image • 2MASS point source at the tip of the CO outflow. • - H2O 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. H2O masers and 2MASS image Multiepoch water masers  (‘’)  (‘’) October 1998 February 1999 April 2003

11. H2O 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 • Bound motions. • Strong interaction between CCS clumps and the outflow. • Compatible with infalling models 10000 AU at 350 pc de Gregorio-Monsalvo, 2004

13. CCS resulting map:

14. CCS resulting map: Plane of the sky

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

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

17. Conclusions: • CCS + NH3 + water maser Dynamics, evolution stage of B1-IRS • Reflection nebula elongated in the same direction of the outflow: CO Outflow near the plane of the sky (2MASS position). • Water masers trace a jet. • CCS emission is clumpy and redshifted. • Gradient in velocity suggest a strong interaction between the CCS and the outflow. • Dynamics compatible with infalling models. • CCS / NH3 anticorrelation at small scales and in star forming regions. de Gregorio-Monsalvo, 2004

18. Futurework: • Combination with single dish data to avoid the missing short spacings in the VLA data: - CCS and NH3 maps with DSN 70 m (Madrid). • NH3 VLA observation in D-configuration: - More integration time. - New receivers. • H2O masers VLA observation in A-configuration or VLBA : - Better precision in position. - Dynamical Structureof the jet. • VLA observation in D-configuration: - New regions with CCS + H2O maser emission detected with DSN 70 m. de Gregorio-Monsalvo, 2004