scholarly journals The Zadko Telescope: Exploring the Transient Universe

Author(s):  
D. M. Coward ◽  
B. Gendre ◽  
P. Tanga ◽  
D. Turpin ◽  
J. Zadko ◽  
...  

AbstractThe Zadko telescope is a 1 m f/4 Cassegrain telescope, situated in the state of Western Australia about 80-km north of Perth. The facility plays a niche role in Australian astronomy, as it is the only meter class facility in Australia dedicated to automated follow-up imaging of alerts or triggers received from different external instruments/detectors spanning the entire electromagnetic spectrum. Furthermore, the location of the facility at a longitude not covered by other meter class facilities provides an important resource for time critical projects. This paper reviews the status of the Zadko facility and science projects since it began robotic operations in March 2010. We report on major upgrades to the infrastructure and equipment (2012–2014) that has resulted in significantly improved robotic operations. Second, we review the core science projects, which include automated rapid follow-up of gamma ray burst (GRB) optical afterglows, imaging of neutrino counterpart candidates from the ANTARES neutrino observatory, photometry of rare (Barbarian) asteroids, supernovae searches in nearby galaxies. Finally, we discuss participation in newly commencing international projects, including the optical follow-up of gravitational wave (GW) candidates from the United States and European GW observatory network and present first tests for very low latency follow-up of fast radio bursts. In the context of these projects, we outline plans for a future upgrade that will optimise the facility for alert triggered imaging from the radio, optical, high-energy, neutrino, and GW bands.

2019 ◽  
Vol 490 (3) ◽  
pp. 3476-3482 ◽  
Author(s):  
I Bartos ◽  
K R Corley ◽  
N Gupte ◽  
N Ash ◽  
Z Márka ◽  
...  

ABSTRACT The recent discovery of TeV emission from gamma-ray bursts (GRBs) by the MAGIC and H.E.S.S. Cherenkov telescopes confirmed that emission from these transients can extend to very high energies. The TeV energy domain reaches the most sensitive band of the Cherenkov Telescope Array (CTA). This newly anticipated, improved sensitivity will enhance the prospects of gravitational-wave follow-up observations by CTA to probe particle acceleration and high-energy emission from binary black hole and neutron star mergers, and stellar core-collapse events. Here we discuss the implications of TeV emission on the most promising strategies of choice for the gravitational-wave follow-up effort for CTA and Cherenkov telescopes more broadly. We find that TeV emission (i) may allow more than an hour of delay between the gravitational-wave event and the start of CTA observations; (ii) enables the use of CTA’s small size telescopes that have the largest field of view. We characterize the number of pointings needed to find a counterpart. (iii) We compute the annual follow-up time requirements and find that prioritization will be needed. (iv) Even a few telescopes could detect sufficiently nearby counterparts, raising the possibility of adding a handful of small-sized or medium-sized telescopes to the network at diverse geographic locations. (v) The continued operation of VERITAS/H.E.S.S./MAGIC would be a useful compliment to CTA’s follow-up capabilities by increasing the sky area that can be rapidly covered, especially in the United States and Australia, in which the present network of gravitational-wave detectors is more sensitive.


Author(s):  
E. J. Howell ◽  
A. Rowlinson ◽  
D. M. Coward ◽  
P. D. Lasky ◽  
D. L. Kaplan ◽  
...  

AbstractThe first observations by a worldwide network of advanced interferometric gravitational wave detectors offer a unique opportunity for the astronomical community. At design sensitivity, these facilities will be able to detect coalescing binary neutron stars to distances approaching 400 Mpc, and neutron star–black hole systems to 1 Gpc. Both of these sources are associated with gamma-ray bursts which are known to emit across the entire electromagnetic spectrum. Gravitational wave detections provide the opportunity for ‘multi-messenger’ observations, combining gravitational wave with electromagnetic, cosmic ray, or neutrino observations. This review provides an overview of how Australian astronomical facilities and collaborations with the gravitational wave community can contribute to this new era of discovery, via contemporaneous follow-up observations from the radio to the optical and high energy. We discuss some of the frontier discoveries that will be made possible when this new window to the Universe is opened.


1986 ◽  
Vol 6 (4) ◽  
pp. 403-415 ◽  
Author(s):  
Martin A. Pomerantz

AbstractThe geographic South Pole, where the United States maintains a year-round scientific station, affords a number of unique advantages for certain types of astronomical observations. These include: continuous viewing and constant declination of ail objects in the southern celestial hemisphere, exceedingly low humidity, extended periods of coronal seeing, high altitude, and uniform terrain. The areas of research that have already benefited immensely from thèse extraordinary features are helioseismology and submillimeter astronomy. Unparalleled observations of global solar oscillations have already yielded significant information about the structure and dynamics of the Sun’s interior. Far infrared measurements of various galactic and extra-galactic regions have attained an unprecedented level of sensitivity, limited for the first time only by the noise inherent in the detector. In addition to further helioseismological observations, currently planned future activities include observational cosmology and ultra high energy gamma ray astronomy.


2012 ◽  
Vol 21 (3) ◽  
Author(s):  
A. M. Mickaelian

AbstractWe review the status of all-sky and large astronomical surveys and their catalogued data over the whole range of electromagnetic spectrum, from gamma-ray to radio, such as ROSAT in X-ray, GALEX in UV, SDSS and several POSS1/2 based catalogs (APM, MAPS, USNO, GSC) in optical, 2MASS and WISE in NIR, IRAS and AKARI in MIR/FIR, NVSS and FIRST in radio range and others. Present astronomical archives contain billions of objects, Galactic as well as extragalactic, and the vast amount of data in them permit new studies and discoveries. Cross-correlations result in revealing new objects and new samples. Very often, dozens of thousands of sources hide a few very interesting ones that are needed to be discovered by comparison of various physical characteristics. Most of the modern databases currently provide VO access to the stored information. This permits not only open access but also fast analysis and managing of these data.


2020 ◽  
Vol 495 (1) ◽  
pp. 1061-1072
Author(s):  
Giacomo Fragione ◽  
Brian D Metzger ◽  
Rosalba Perna ◽  
Nathan W C Leigh ◽  
Bence Kocsis

ABSTRACT Mergers of binaries comprising compact objects can give rise to explosive transient events, heralding the birth of exotic objects that cannot be formed through single-star evolution. Using a large number of direct N-body simulations, we explore the possibility that a white dwarf (WD) is dynamically driven to tidal disruption by a stellar-mass black hole (BH) as a consequence of the joint effects of gravitational wave (GW) emission and Lidov–Kozai oscillations imposed by the tidal field of an outer tertiary companion orbiting the inner BH–WD binary. We explore the sensitivity of our results to the distributions of natal kick velocities imparted to the BH and WD upon formation, adiabatic mass loss, semimajor axes and eccentricities of the triples, and stellar-mass ratios. We find rates of WD–tidal disruption events (TDEs) in the range 1.2 × 10−3 − 1.4 Gpc−3 yr−1 for z ≤ 0.1, rarer than stellar TDEs in triples by a factor of ∼3–30. The uncertainty in the TDE rates may be greatly reduced in the future using GW observations of Galactic binaries and triples with LISA. WD–TDEs may give rise to high-energy X-ray or gamma-ray transients of duration similar to long gamma-ray bursts but lacking the signatures of a core-collapse supernova, while being accompanied by a supernova-like optical transient that lasts for only days. WD–BH and WD–NS binaries will also emit GWs in the LISA band before the TDE. The discovery and identification of triple-induced WD–TDE events by future time domain surveys and/or GWs could enable the study of the demographics of BHs in nearby galaxies.


2004 ◽  
Vol 218 ◽  
pp. 13-20 ◽  
Author(s):  
Michael Kramer

The largest number of known young neutron stars axe observed as spin-powered pulsars. While the majority of those are detected at radio frequencies, an increasing number can be studied in other parts of the electromagnetic spectrum as well. The Crab pulsar is the prototype of a young pulsar which can be observed from radio to gamma-ray frequencies, providing a red thread of discussion during a tour through the pulsar properties observed across the electromagnetic spectrum. The basic observational features of pulsar emission are presented, preparing the ground for more detailed reviews given in these proceedings. Here, particular attention will be paid to those emission features which may provide a link between the radio and high-energy emission processes.


2019 ◽  
Vol 208 ◽  
pp. 14009
Author(s):  
V.G. Sinitsyna ◽  
V.Y. Sinitsyna ◽  
K.A. Balygin ◽  
S.S. Borisov ◽  
A.M. Kirichenko ◽  
...  

The Cygnus Region is one of the brightest regions in all ranges of the electromagnetic spectrum and contains a number of potential GeV and TeV emission sources. It includes active star formation regions, pulsars and supernova remnants. Some of the sources have been detected at high and very high energies. One of them discovered due to its proximity to the well-known microquasar Cyg X-3 is the object TeV J2032+4130. This object is still of unresolved nature and is being intensively studied in different energy ranges. The results of twenty-year observations of TeV J2032+4130 by the SHALON experiment are presented in this paper. The collected experimental data on fluxes, spectrum shape and morphology of TeV J2032+413 can help in the future to determine an object type and reveal mechanisms of generation of very high energy emission.


2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Javier Gorosabel ◽  
Petr Kubánek ◽  
Martin Jelínek ◽  
Alberto J. Castro-Tirado ◽  
Antonio de Ugarte Postigo ◽  
...  

We report on optical observations of Gamma-Ray Bursts (GRBs) followed up by our collaboration with the 1.23 m telescope located at the Calar Alto observatory. The 1.23 m telescope is an old facility, currently undergoing upgrades to enable fully autonomous response to GRB alerts. We discuss the current status of the control system upgrade of the 1.23 m telescope. The upgrade is being done by our group based on the Remote Telescope System, 2nd Version (RTS2), which controls the available instruments and interacts with the EPICS database of Calar Alto. (Our group is called ARAE (Robotic Astronomy & High-Energy Astrophysics) and is based on members of IAA (Instituto de Astrofísica de Andalucía). Currently the ARAE group is responsible to develop the BOOTES network of robotic telescopes (Jelínek et al. 2009).) Currently the telescope can run fully autonomously or under observer supervision using RTS2. The fast reaction response mode for GRB reaction (typically with response times below 3 minutes from the GRB onset) still needs some development and testing. The telescope is usually operated in legacy interactive mode, with periods of supervised autonomous runs under RTS2. We show the preliminary results of several GRBs followed up with observer intervention during the testing phase of the 1.23 m control software upgrade.


2019 ◽  
Vol 486 (2) ◽  
pp. 2471-2476 ◽  
Author(s):  
B Gendre ◽  
Q T Joyce ◽  
N B Orange ◽  
G Stratta ◽  
J L Atteia ◽  
...  

Abstract Ultra-long gamma-ray bursts are a class of high-energy transients lasting several hours. Their exact nature is still elusive, and several models have been proposed to explain them. Because of the limited coverage of wide-field gamma-ray detectors, the study of their prompt phase with sensitive narrow-field X-ray instruments could help in understanding the origin of ultra-long GRBs. However, the observers face a true problem in rapidly activating follow-up observations, due to the challenging identification of an ultra-long GRB before the end of the prompt phase. We present here a comparison of the prompt properties available after a few tens of minutes of a sample of ultra-long GRBs and normal long GRBs, looking for prior indicators of the long duration. We find that there is no such clear prior indicator of the duration of the burst. We also found that statistically, a burst lasting at least 10 and 20 minutes has respectively $28{{\ \rm per\ cent}}$ and $50{{\ \rm per\ cent}}$ probability to be an ultralong event. These findings point towards a common central engine for normal long and ultra-long GRBs, with the collapsar model privileged.


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