Presentation on theme: "A Search For Interstellar Urea With CARMA Hsin-Lun Kuo, Lewis Snyder, Douglas Friedel, Leslie Looney, Benjamin McCall (UIUC), Anthony Remijan (NRAO), Frank."— Presentation transcript:
A Search For Interstellar Urea With CARMA Hsin-Lun Kuo, Lewis Snyder, Douglas Friedel, Leslie Looney, Benjamin McCall (UIUC), Anthony Remijan (NRAO), Frank Lovas (NIST), Jan Hollis (NASA)
Motivation Urea (NH 2 ) 2 CO has measured and calculated laboratory frequencies good to a few kHz. In preparation of CARMA search for protonated methanol (frequencies measured by McCall group), we wish to develop procedures with trustworthy calibrator fluxes, proper baseline subtraction, and self calibration to extract weak emission lines from CARMA data.
CARMA ( Combined Array for Research in Millimeter- wave Astronomy ) Owens Valley Radio Observatory (OVRO) -- 10.4 m X6 Berkeley-Illinois-Maryland Association (BIMA) -- 6.1 m X9 105 baselines Angular resolution about 0.3", 0.8", 2", 5", or 10" at 100 GHz in A, B, C, D, and E configuration Operates at 3 mm (85-116 GHz) and 1 mm (215-270 GHz)
Conclusion Rotational temperature T rot ~ 80K Linewidth v ~ 2.05 km s -1 Beam-averaged total column density N tot = 9.75 10 14 cm -2 Proper coupling of source size to the beam size is essential for flux measurements and detection limits; it helps bring out weak signals that are otherwise blended with extended emission.