Blazar variability studies with the 1.3 m Robotically Controlled Telescope and the automated 0.6 m Bell Observatory telescope

Abstract

Abstract.One of the key programs on the 1.3m Robotically Controlled Telescope (RCT) located at Kitt Peak National Observatory and the 0.6m telescope at the Bell Observatory operated by Western Kentucky University is a study of the variability of the class of Active Galactic Nuclei (AGN) known as Blazars. Blazars are highly variable on timescales of minutes to decades and this variability is seen across the electromagnetic spectrum. In addition, they display a featureless spectrum, thus continuum variability provides the only diagnostic of these objects. Variability provides information on the size of the emission region responsible for the observed variations and when observations are obtained at multiple wavelengths, it can be used to discriminate between emission models. However, traditional ground based observations are limited in a variety of ways. We will discuss how an automated facility, with time dedicated to this astrophysically interesting problem, can overcome many of these limitations, and we show results from the Bell Observatory as well as some of the first results of Blazar observations from the RCT.

An optical view of BL Lacertae objects

“…Gamma-Ray Bursts), has greatly benefitted the BLL field. These small telescopes (e.g., REM, ROTSE, SMARTS) have flexible schedules and pointing constraints, therefore they can be devoted to long looks of variable sources like BLLs (Tosti et al, 1996;Ciprini et al, 2003;Carini et al, 2004;Gu et al, 2006;Dolcini et al, 2007;Kastendieck et al, 2011;Ackermann et al, 2012;Bonning et al, 2012;Nesci et al, 2013;Sandrinelli et al, 2014).…”

THE RCT 1.3 m ROBOTIC TELESCOPE: BROADBAND COLOR TRANSFORMATION AND EXTINCTION CALIBRATION

“…The Robotically Controlled Telescope (or RCT) is operated by an automated and efficient scheduler, and equipped with a suite of broad and narrow-band filters to enable 'snapshot' imaging and monitoring on a range of time-scales. The telescope supports the broad interests of the investigators and institutions comprising the RCT Consortium, and has already contributed to the locating and monitoring of gamma-ray bursts and supernovae (McGruder et al 2004b;Gouravajhala et al 2012;Gott et al 2012), ephemerides of minor planets (e.g., Buie et al 2013), and the monitoring of variable stars and active galaxies (Engle & Guinan 2011;Lefèvre et al 2005;Marchenko et al 2004;Raiteri et al 2006;Carini et al 2004). The RCT is also regularly used in undergraduate research at Consortium institutions, and frequently contributes to science education and outreach in programs such as the Arizona Astronomy Camp (McCarthy 2011).…”

“…The automated scheduling of the RCT, as discussed further in §2.2, is efficient enough to wedge small programs between optimal windows of larger ones, repurpose windows of failed observations, and utilize fractions of nights in marginal or sub-optimal conditions which might otherwise be lost. This, in combination with options for repeated requests allows a regular monitoring of blazars ad perpetuum, and provides well-sampled long-term light curves for complementary studies with, for example, RXTE, VERITAS, and Fermi (Carini et al 2004). Light Curves of Supernovae and Gamma-Ray Bursts: Both gamma-ray bursts and supernovae are now routinely discovered at a rate several hundred per year, respectively, now enabling a more comprehensive understanding of the nature of these extremely energetic explosions.…”