Astronomical instrumentation

Abstract:

We present near infrared observations of IRAS 04302+2247, a Class I protostar in the Taurus-Auriga molecular cloud complex whose equatorial plane is inclined precisely edge-on to the line of sight (i = 90 degrees +/- 4 degrees). This system displays a unique quadrupolar morphology, which had not been previously predicted in any simulations of a single protostar. We use the Monte Carlo method to tailor a model to our imaging and polarimetric data, and we explain the quadrupolar structure in terms of a dusty jet or outflow which lies perpendicular to the equatorial plane. We constrain the circumstellar structure to the form of an equatorially condensed envelope with a concave bipolar cavity. The circumstellar disk is not seen, which requires that it is physically thin. With its convenient orientation and proximity (d = 140pc) this system should yield many insights into the Class I phase of evolution.

Abstract:

We report 1'' K-band imaging spectroscopy of the z=2.284 galaxy IRAS F10214+4724. We find that the rest-frame H alpha and [N II] emission have different spatial extents. Furthermore, we detect broad (Delta upsilon(FWZP)approximate to 3500 km s(-1)) H alpha emission. We conclude that F10214+4724 is a very luminous gravitationally lensed galaxy, which intrinsically contains both a type 1 AGN and a more extended star-forming disk. The AGN and circumnuclear star formation both contribute significantly to the total luminosity of similar to 10(13)L(circle dot).

Abstract:

We have imaged a compact stellar cluster, with a characteristic size of 50 pc, toward the nucleus of NGC 1068, using near IR imaging spectroscopy of stellar absorption features in the H and K bands. The near IR stellar light is attributed to a population of late type stars, with an average spectral type of M0. Based on light-to-mass ratio measurements, we derive an upper limit for the age of the nuclear cluster of 4 x 10(9) years. The stellar cluster contributes a non-negligible fraction of the total nuclear bolometric luminosity, a value of 5% being a very conservative lower limit. The compact stellar distribution identifies the dynamical center of the galaxy as being coincident with the peak of the It band emission. The morphology of the excited molecular gas, revealed by mapping the H-2 S(1) line at 2.12 mu m, shows a molecular ring with a radius of similar to 100 pc. Millimeter interferometric imaging in the CO J = 2 --> 1 transition at 1.3 mm shows the ring to be rotating with velocities of similar to 100 km s(-1).