| Authors : | Author(s): Sarang Shah1, Smitha Subramanian2, G. C. Anupama2, Francisco Delgado3, Kim Gillies3, Maheswar Gopinathan2, Rajalakshmi Narayanan1, A. N. Ramaprakash4, Suhasini Rao2, B. E. Reddy2, Warren Skidmore3, T. Sivarani2, Annapurni Subramaniam2
(1) India TMT Coordination Center (ITCC), India
(2) Indian Institute of Astrophysics (IIA), India
(3) TMT Project Office, USA
(4) Inter-University Center for Astronomy and Astrophysics (IUCAA), India
|
| Abstract : | At first light, the NIR instruments of TMT will be assisted by a multi-conjugate AO instrument, known as the Narrow Field Infrared Adaptive Optics System (NFIRAOS). NFIRAOS will use laser guide stars for distortion correction in a field of view of 2 arcmin diameter, but tip and tilt errors of the telescope will be corrected by the natural guide stars. A guide star catalogue with NIR magnitudes as faint as 22 mags in J band (Vega system), covering the TMT-observable sky will be a critical resource for the efficient operation of NFIRAOS. No catalogue currently exists with objects as faint as JVega = 22 mag over the entire TMT observable sky. Hence it is essential to develop such a catalogue by computing the expected NIR magnitudes of stellar sources, identified in deep optical sky surveys, by using their optical magnitudes. In this talk, we will discuss a road map created for the generation of the Infrared Guide Star Catalogue (IRGSC) for the TMT using the optical data of stellar sources from Pan-STARRS and computing their NIR magnitudes by using stellar atmospheric models and Spectral Energy Distribution (SED) fits. We validated the computed NIR magnitudes of sources in some fields by using the available NIR data for those fields. We find our method to be satisfactory, thereby creating a path for the final production of the IRGSC using the Pan-STARRS. We will present a partial catalogue and a user interface to select guide stars from it. We also put forward the challenges that need to be overcome in the future development of IRGSC. |
