Publications of the Astronomical Society of the Pacific

Sozzetti, Alessandro

doi: 10.1086/444487pmid: N/A

I present a review of astrometric techniques and instrumentation used to search for, detect, and characterize extrasolar planets. First, I briefly summarize the properties of the current sample of extrasolar planets, in connection with predictions from theoretical models of planet formation and evolution. Next, the generic approach to planet detection with astrometry is described, with significant discussion of a variety of technical, statistical, and astrophysical issues to be faced by future ground‐based and space‐borne efforts in order to achieve the required degree of measurement precision. After a brief summary of past and present efforts to detect planets via milliarcsecond astrometry, I then discuss the planet‐finding capabilities of future astrometric observatories aiming at microarcsecond precision. Finally, I outline a number of experiments that can be conducted by means of high‐precision astrometry during the next decade, to illustrate its potential for important contributions to planetary science, compared to other indirect and direct methods for the detection and characterization of planetary systems.

Sirianni, M.; Jee, M. J.; Benítez, N.; Blakeslee, J. P.; Martel, A. R.; Meurer, G.; Clampin, M.; De Marchi, G.; Ford, H. C.; Gilliland, R.; Hartig, G. F.; Illingworth, G. D.; Mack, J.; McCann, W. J.

Makovoz, David; Marleau, Francine R.

doi: 10.1086/432977pmid: N/A

MOPEX (Mosaicking and Point‐source Extraction) is a package developed at the Spitzer Science Center for astronomical image processing. We report on the point‐source extraction capabilities of MOPEX. Point‐source extraction is implemented as a two‐step process: point‐source detection and profile fitting. Nonlinear matched filtering of input images can be performed optionally to increase the signal‐to‐noise ratio and improve detection of faint point sources. Point response function (PRF) fitting of point sources produces the final point‐source list, which includes the fluxes and improved positions of the point sources, along with other parameters characterizing the fit. Passive and active deblending allows for successful fitting of confused point sources. Aperture photometry can also be computed for every extracted point source for an unlimited number of aperture sizes. The PRF is estimated directly from the input images. The implementation of efficient methods of background and noise estimation and a modified simplex algorithm contribute to the computational efficiency of MOPEX. The package is implemented as a loosely connected set of Perl scripts, each script running a number of modules written in C/C++. Input parameter setting is done through name lists, ASCII configuration files. We present applications of point‐source extraction to the mosaic images taken at 24 and 70 μm with the Multiband Imaging Photometer (MIPS) as part of the Spitzer extragalactic First Look Survey, and to a Digital Sky Survey image. Completeness and reliability of point‐source extraction is computed using simulated data.

Vincent, Mark B.; Chanover, Nancy J.; Beebe, Reta F.; Huber, Lyle

doi: 10.1086/444486pmid: N/A

The NASA Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii, set aside some time on about 500 nights from 1995 to 2002, when the NSFCAM facility infrared camera was mounted and Jupiter was visible, for a standardized set of observations of Jupiter in support of the Galileo mission. The program included observations of Jupiter, nearby reference stars, and dome flats in five filters: narrowband filters centered at 1.58, 2.28, and 3.53 μm, and broader L′ and M′ bands that probe the atmosphere from the stratosphere to below the main cloud layer. The reference stars were not cross‐calibrated against standards. We performed follow‐up observations to calibrate these stars and Jupiter in 2003 and 2004. We present a summary of the calibration of the Galileo support monitoring program data set. We present calibrated magnitudes of the six most frequently observed stars, calibrated reflectivities, and brightness temperatures of Jupiter from 1995 to 2004, and a simple method of normalizing the Jovian brightness to the 2004 results. Our study indicates that the NSFCAM's zero‐point magnitudes were not stable from 1995 to early 1997, and that the best Jovian calibration possible with this data set is limited to about ±10%. The raw images and calibration data have been deposited in the Planetary Data System.

Canizares, Claude R.; Davis, John E.; Dewey, Daniel; Flanagan, Kathryn A.; Galton, Eugene B.; Huenemoerder, David P.; Ishibashi, Kazunori; Markert, Thomas H.; Marshall, Herman L.; McGuirk, Michael; Schattenburg, Mark L.; Schulz, Norbert S.; Smith, Henry I.; Wise, Michael