RATIR will observe early Gamma-Ray Burst (GRB) afterglows in 6
simultaneous optical/NIR colors to weed out high-z bursts, enabling
use of GRBs as potential probes to the epoch of reinionization in the
early Universe.

SPIE instrument papers:
Commissioning and First Light (Butler et al. 2012), Mechanical design (Farah et al. 2012), Telescope and automation (Watson et al. 2012), Software (Klein et al. 2012), NIR detectors (Fox et al. 2012)

See the RATIR wiki at UNAM for instrument and observing details.


04/24/2012 NIR cameras mounted on the telescope.

02/17-20/2012, Optical Cameras Installed on the 1.5m.

Deployment to San Pedro Martir planned for Spring 2012

Jan. 11, 2012. Image of the trapezium in orion, captured with the La Ruca camera on the 1.5 m during automation testing of the telescope prior to RATIR delivery. (10 second exposure, narrow-band 895 nm filter; Note: pixels are 0.25 arcsec, implying 0.79 arcsec FWHM seeing; fits image ).

Preliminary Design Review Documentation : May 12, UC Santa Cruz (here).

Pics of Recent Trip to San Pedro Martir Observatory : here .

Conceptual Design Review Documentation : April 17, UC Santa Cruz (here).

Some headshots with the Finger Lakes ProLine broadband (RATIR i-band) Camera : here.


The RATIR camera consists of two optical and two IR arms, with a two-color split filter directly above each detector in the IR arms to allow for simultaneous imaging in six colors (two optical and four NIR). The converging incoming beam from the 1.5m telescope's (see below) F/13 secondary is first separated by a dichroic between i and z bands. The optical light (r and i bands) are further split by a dichroic. The IR light is split between Y and J bands by a dichroic into the Y + z and J + H bands (designed by J. J. Gonzalez, UNAM).
The 1.5 meter telescope we propose to use is located at the Mexican Observatorio Astronomico Nacional (OAN) on the Sierra San Pedro Martir (SPM) in Baja California (see here), about 250 km South of San Diego.

The observatory has been developed over the last forty years by the UNAM and has 2.1, 1.5, and 0.8 meter telescopes. Comparison with other sites suggests that SPM has the largest fraction of clear nights of any site in the northern hemisphere.

First light is planned for early 2011.

Sensitivity to high-z GRBs.

RATIR and the 1.5m telescope at SPM will be dedicated to Swift GRB followup for a period of 2 years. Scaling from experience with PAIRITEL, we expect to observe about 12 Swift bursts per year within 10 minutes, and about 15 within 1 hour.

The expected detectability limits are H=20.3 and J=20.9 (AB mags), within 10 minutes of a GRB.

Last Updated: Fri Jan 20 18:58:39 UTC 2012

Nat Butler (nat@astro.berkeley.edu)