Observational Astronomy in New Mexico: The ARC 3.5m Telescope at Apache Point Observatory

The 3.5m telescope at Apache Point Observatory (APO) is owned and operated by the Astrophysical Research Consortium (ARC), a consortium of nine universities who contribute to the annual operating costs in exchange for access to telescope time. Located in the Sacramento Mountains of southern New Mexico at an elevation of 2788 m, APO is home to the ARC 3.5m as well as the Sloan Foundation 2.5m telescope used for the Sloan Digital Sky Survey, the NMSU 1m telescope, and the 0.5m ARC Small Aperture Telescope. The 3.5m is an f/10 alt-az telescope that features several instrument ports that allow for rapid (< 15 minute) instrument changes. There are currently seven facility instruments available for use on the 3.5m: three spectrographs (two long-slit optical, one optical echelle with R ~ 31,500, and one medium resolution covering JHK) and three imagers (one high speed optical imager, one optical imager with a 7.5’ FOV, and one NIR imager). The 3.5m was designed with remote observing capability from the outset, making it an easily accessible observing facility for ARC partners geographically distributed across the United States. Since 2006 the 3.5m has also hosted a lunar laser ranging experiment, APOLLO, which has yielded some of the most accurate lunar distance measurements to date. Since the beginning of 3.5m operations in 1994 APO has maintained an impressive level of scientific productivity, resulting in roughly 600 papers in refereed journals and more than 40 Ph.D. dissertations. It has served as a major follow-up resource for discoveries made with SDSS, and it is poised to play a significant role in follow-up observations of numerous discoveries in the new era of time domain astronomy. Its ability to accommodate guest instruments has also made it an attractive facility for technology demonstrations and instrument development initiatives. Additionally, the 3.5m has served as a valuable educational and training tool for undergraduate and graduate students from ARC member institutions and leasing partners. We present some recent scientific highlights from APO and discuss new future directions for the observatory in terms of scientific, instrumentation and educational initiatives.