CCS in low mass star forming regions:
Radioastronomy in the MDSCC
Itziar de Gregorio-Monsalvo
LAEFF-INTA (Spain)
José F. Gómez, LAEFF-INTA
Olga Suarez, LAEFF-INTA
Thomas B. Kuiper, JPL-NASA
NASA Deep Space Network
NASA DSN
Madrid, Spain
• World-wide network
• Three main complexes
• Tracking of NASA´s spacecrafts
Goldstone, USA
• MDSCC, INTA-JPL
• Host-country: 4% total time
for radioastronomy
Camberra, Australia
de Gregorio-Monsalvo, JENAM 2004
First Radioastronomy survey in the MDSCC
Engineers
Scientists
NASA - INTA
T. Kuiper (JPL)
J.F. Gómez (INTA-LAEFF)
O. Suarez (INTA-LAEFF)
I. de Gregorio (INTA-LAEFF)
The team
Operators
The observations:
- 70 m antenna
- K-band (18-26 GHz)
- Spectroscopy: Digital autocorrelator, 1024
channels, 4 different bandwidths
- Future Q-band receivers (45 GHz)
.............You can ask for time!!!!!
Robledo de Chavela
70-m antenna, Madrid
http://www.laeff.esa.es
de Gregorio-Monsalvo, JENAM 2004
Why CCS is so interesting?
• Molecular lines provide information about T, density and kinematics.
• CCS is a powerful tool to study YSOs:
1. Structure and physical conditions of the cloud.
2. Dynamics and interaction with the medium.
• Intense in cold quiescent cores (Suzuki, 1992).
• Spatial anticorrelation between CCS and ammonia
clock to test age.
• Star formation :
- CCS destructionn
- Ammonia desorption
• [CCS] / [NH3] indicator of cloud
evolution
(Suzuki et al. 1992)
CCS survey in low mass protostars
• If CCS is a youth tracer it should be associated to youngest class 0 sources
• Water masers as tracer of youth:
40% class 0 sources harbour water masers
4% class I
0% class II (Furuya 2001)
• Our survey: 44 low mass protostar that harbour water masers.
• CCS + water masers
Youngest protostars
RESULT:
9 CCS detections
75% class 0 sources, 25% class I sources
1 detection in a possible medium-high mass region.
de Gregorio-Monsalvo, JENAM 2004
CCS detections in class 0 sources:
L1448C / L1448-IRS3
(Curiel 1990, Bachiller 1990)
B1- IRS
L1157
S68 FIR-1
(Bachiller 1997)
(Davis 1999)
GF9-2
- Very young class 0 source.
- Weak outflow (Furuya 2001).
(Hirano 1997)
de Gregorio-Monsalvo, JENAM 2004
CCS in class I and high mass protostars
Class I sources
Medium-high mass region?
NGC2071-N
L43
(Mathieu 1988)
NGC2071
(Torrelles 1998)
(Iwata 1988)
Strong interaction with the medium
First CCS detection in a
medium-high mass region!!
de Gregorio-Monsalvo, JENAM 2004
Survey results:
• Emission in class 0 sources associated to spectacular outflows.
• Emission in class I sources associated to regions with strong interaction
with the medium
INTERPRETATION:
- CCS emission could be not only dependent of the age
Statistical study
- CCS could be formed in older regions via dinamycal-chemical processes
- Revision of the classification of the class I sources.
de Gregorio-Monsalvo, JENAM 2004
B1-IRS (IRAS 03301+3057): VLA observations
• Goals:
1- Study the dynamics, evolution and interaction at high resolution.
2- Test CCS vs NH3 in star forming regions at high resolution:
- VLA-D configuration ammonia archive data
3- Test a new observation technique: cross-calibration in spectral line.
- Similar to adaptive optics.
- Simultaneous observations of CCS (22.35 GHz)
and H2O (22.24 GHz).
- 4 IF spectral line mode, VLA-D configuration.
de Gregorio-Monsalvo, JENAM 2004
H2O masers and 2MASS image
Hirano et al, 1997
- 2MASS point source at the tip of the CO outflow. Reflection nebula in Kband image
- H2O masers located at 1” in an elongated structure. Unbound motions,
probably tracing a jet .
- Lack of velocity gradient ( Outflow lies nearer the plane of the sky ? ).
H2O masers and 2MASS image
- 2MASS point source at the tip of the CO outflow. Reflection nebula in Kband image
- H2O masers located at 1” in an elongated structure. Unbound motions,
probably tracing a jet .
- Lack of velocity gradient ( Outflow lies nearer the plane of the sky ? ).
CCS resulting map:
- CCS emission is clumpy.
- Redshifted clumps.
10000 AU at 350 pc
- Velocity gradient blue-shifted
towards the central source
- Strong interaction between CCS
clumps and the outflow.
de Gregorio-Monsalvo, JENAM 2004
Interpretations:
Plane of the sky
Interpretations:
Plane of the sky
Ammonia vs CCS:
....Anticorrelation!!!!
de Gregorio-Monsalvo, JENAM 2004
Future work:
work
• High resolution observations in other sources:
- Dynamics
- Anticorrelations.
• Test the cross-calibration technique.
• Statistical study with the single dish data.
de Gregorio-Monsalvo, JENAM 2004