scholarly journals Optical pulsars and polarimetry

2017 ◽  
Vol 13 (S337) ◽  
pp. 191-194 ◽  
Author(s):  
Andrew Shearer ◽  
Eoin O’ Connor
Keyword(s):  
Gamma Ray ◽  
Optical Observations ◽  
Crab Pulsar ◽  
Optical Detectors ◽  
X Ray ◽  
First Order ◽  
Near Ir ◽  
Large Telescopes ◽  
Optical Telescopes ◽  
Polarisation Measurements

AbstractDespite the early optical detection of the Crab pulsar in 1969, optical pulsars have become the poor cousin of the neutron star family. Only five normal pulsars have been observed to pulse in the optical waveband. A further three magnetars/SGRs have been detected in the optical/near IR. Optical pulsars are intrinsically faint with a first order luminosity, predicted by Pacini, to be proportional to P−10, where P is the pulsar’s period. Consequently they require both large telescopes, generally over-subscribed, and long exposure times, generally difficult to get. However optical observations have the benefit that polarisation and spectral observations are possible compared to X-ray and gamma-ray observations where polarisation measurements are limited. Over the next decade the number of optical pulsars should increase as optical detectors approach 100% quantum efficiency and as we move into the era of extremely large telescopes where limiting fluxes will be 30 to 100 times fainter compared to existing optical telescopes.

scholarly journals Gamma-Ray Bursts in the Era of Rapid Followup

2010 ◽  
Vol 2010 ◽  
pp. 1-14 ◽  
Author(s):  
C. G. Mundell ◽  
C. Guidorzi ◽  
I. A. Steele
Keyword(s):  
Real Time ◽  
Gamma Ray ◽  
Early Time ◽  
Gamma Ray Bursts ◽  
Light Curves ◽  
Optical Observations ◽  
Status Report ◽  
The Novel ◽  
Optical Telescopes ◽  
Polarisation Measurements

We present a status report on the study of gamma-ray bursts (GRBs) in the era of rapid followup using the world's largest robotic optical telescopes—the 2 m Liverpool and Faulkes telescopes. Within the context of key unsolved issues in GRB physics, we describe (1) our innovative software that allows real-time automatic analysis and interpretation of GRB light curves, (2) the novel instrumentation that allows unique types of observations (in particular, early time polarisation measurements), and (3) the key science questions and discoveries to which robotic observations are ideally suited, concluding with a summary of current understanding of GRB physics provided by combining rapid optical observations with simultaneous observations at other wavelengths.

X-ray and optical observations of the November 19, 1978 Gamma-Ray Burst source region

1981 ◽  
Vol 30 (1-4) ◽  
pp. 467-470 ◽  
Author(s):  
G. Pizzichini ◽  
J. Danziger ◽  
P. Grosb� ◽  
M. Tarenghi ◽  
T. L. Cline ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Source Region ◽  
Optical Observations ◽  
Burst Source ◽  
Gamma Ray Burst ◽  
X Ray

Swift observations of gamma-ray bursts

2007 ◽  
Vol 365 (1854) ◽  
pp. 1119-1128 ◽  
Author(s):  
Neil Gehrels
Keyword(s):  
Gamma Ray ◽  
High Redshift ◽  
Gamma Ray Bursts ◽  
Optical Observations ◽  
Nearby Galaxy ◽  
X Ray ◽  
Star Forming ◽  
Star Forming Regions ◽  
Other Information ◽  
Short Grbs

Since its launch on 20 November 2004, the Swift mission has been detecting approximately 100 gamma-ray bursts (GRBs) each year, and immediately (within approx. 90 s) starting simultaneous X-ray and UV/optical observations of the afterglow. It has already collected an impressive database, including prompt emission to higher sensitivities than BATSE, uniform monitoring of afterglows and a rapid follow-up by other observatories notified through the GCN. Advances in our understanding of short GRBs have been spectacular. The detection of X-ray afterglows has led to accurate localizations and the conclusion that short GRBs can occur in non-star-forming galaxies or regions, whereas long GRBs are strongly concentrated within the star-forming regions. This is consistent with the NS merger model. Swift has greatly increased the redshift range of GRB detection. The highest redshift GRBs, at z ∼5–6, are approaching the era of reionization. Ground-based deep optical spectroscopy of high redshift bursts is giving metallicity measurements and other information on the source environment to a much greater distance than other techniques. The localization of GRB 060218 to a nearby galaxy, and the association with SN 2006aj, added a valuable member to the class of GRBs with detected supernova.

X-Ray and Optical Observations of the November 19, 1978 Gamma-Ray Burst Source Region

1981 ◽  
pp. 467-470
Author(s):  
G. Pizzichini ◽  
J. Danziger ◽  
P. Grosbøl ◽  
M. Tarenghi ◽  
T. L. Cline ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Source Region ◽  
Optical Observations ◽  
Burst Source ◽  
Gamma Ray Burst ◽  
X Ray

scholarly journals An unusual transient following the short GRB 071227

2019 ◽  
Vol 489 (1) ◽  
pp. 13-27
Author(s):  
R A J Eyles ◽  
P T O’Brien ◽  
K Wiersema ◽  
R L C Starling ◽  
B P Gompertz ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Thermal Emission ◽  
Chemical Properties ◽  
Major Axis ◽  
Optical Observations ◽  
X Ray ◽  
Very Large Telescope ◽  
The Galaxy ◽  
Simple Extrapolation ◽  
Emission Models

ABSTRACT We present X-ray and optical observations of the short duration gamma-ray burst GRB 071227 and its host at z = 0.381, obtained using Swift, Gemini South, and the Very Large Telescope. We identify a short-lived and moderately bright optical transient, with flux significantly in excess of that expected from a simple extrapolation of the X-ray spectrum at 0.2–0.3 d after burst. We fit the SED with afterglow models allowing for high extinction and thermal emission models that approximate a kilonova to assess the excess’ origins. While some kilonova contribution is plausible, it is not favoured due to the low temperature and high luminosity required, implying superluminal expansion and a large ejecta mass of ∼0.1 M$\odot$. We find, instead, that the transient is broadly consistent with power-law spectra with additional dust extinction of E(B − V) ∼ 0.4 mag, although a possibly thermal excess remains in the z band. We investigate the host, a spiral galaxy with an edge-on orientation, resolving its spectrum along its major axis to construct the galaxy rotation curve and analyse the star formation and chemical properties. The integrated host emission shows evidence for high extinction, consistent with the afterglow findings. The metallicity and extinction are consistent with previous studies of this host and indicate the galaxy is a typical, but dusty, late-type SGRB host.

scholarly journals A multi-wavelength campaign to study giant pulses from the Crab Pulsar

2012 ◽  
Vol 8 (S291) ◽  
pp. 322-322 ◽  
Author(s):  
Walid Majid
Keyword(s):  
Gamma Ray ◽  
Correlation Study ◽  
Crab Pulsar ◽  
X Ray ◽  
Frequency Detection ◽  
Giant Pulses ◽  
Upper Limit ◽  
The Status ◽  
Multi Wavelength ◽  
Flux Increase

AbstractWe are currently undertaking a monitoring campaign with NASA 70-m antennas to capture a large sample of Crab Giant Pulses (CGP) at multiple radio wavelengths. The goal of this campaign is to carry out a correlation study of CGPs at radio frequencies with pulsed emission from the Crab pulsar with Fermi photons at X-ray. After a year of this study, we expect around 200 Fermi photons to coincide with a CGP radio-frequency detection, allowing us to either confirm a predicted correlation in average gamma-ray pulsed flux increase with GP emission, or place a tight upper limit, at least a factor of 10 more constraining than previous work. We will report on the status of this campaign and will present our preliminary results and prospects for future improvements in receivers and back-end instrumentation.

scholarly journals TOWARD IDENTIFYING THE UNASSOCIATED GAMMA-RAY SOURCE 1FGL J1311.7-3429 WITH X-RAY AND OPTICAL OBSERVATIONS

2012 ◽  
Vol 757 (2) ◽  
pp. 176 ◽  
Author(s):  
J. Kataoka ◽  
Y. Yatsu ◽  
N. Kawai ◽  
Y. Urata ◽  
C. C. Cheung ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Optical Observations ◽  
X Ray

scholarly journals Capabilities of the Optical Monitor for the Research in X-Ray Source and Stellar Variability

1993 ◽  
Vol 134 ◽  
pp. 235-237
Author(s):  
E. Antonello ◽  
L. Maraschi ◽  
O. Citterio
Keyword(s):  
Weather Conditions ◽  
Space Mission ◽  
Complete Data ◽  
Optical Observations ◽  
X Ray ◽  
Substantial Loss ◽  
Small Telescope ◽  
Scientific Potential ◽  
Data Coverage ◽  
Optical Telescopes

The project of an Optical Monitor (OM) for X-ray satellites, in particular the JET-X (Joint European Telescope for X-ray astronomy) experiment (Wells et al., 1991), derives from the scientific need of having complete data coverage at various wavelengths, UV and optical, of the observed X-ray sources, because these data are essential for a deeper understanding of the various classes of objects. When studying variable sources and/or transient astronomical phenomena, one needs that the multifrequency observations be performed essentially at the same time, because it is the knowledge of the simultaneous optical and X-ray behaviour of a source which contributes substantially to the clarification of its nature. In principle optical observations simultaneous with X-ray ones can be performed from ground based telescopes. However the complexity of satisfying the constraints typical of the optical telescopes (weather conditions, source observability) and of the X-ray instrumentation (e.g. orbital constraints) lead inevitably to a substantial loss of observing time. Therefore the only practical way of having an optimal utilization of the time available for X-ray observations, together with the wealth of scientific potential of simultaneous UV-optical observations, is to have a small telescope to be part of the same space mission.

scholarly journals A Revisit of the Phase‐resolved X‐Ray and Gamma‐Ray Spectra of the Crab Pulsar

2008 ◽  
Vol 676 (1) ◽  
pp. 562-572 ◽  
Author(s):  
Anisia P. S. Tang ◽  
J. Takata ◽  
J. J. Jia ◽  
K. S. Cheng
Keyword(s):  
Gamma Ray ◽  
Crab Pulsar ◽  
X Ray
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