scholarly journals The Science Case for PILOT II: the Distant Universe

2009 ◽  
Vol 26 (4) ◽  
pp. 397-414 ◽  
Author(s):  
J. S. Lawrence ◽  
M. C. B. Ashley ◽  
A. Bunker ◽  
R. Bouwens ◽  
D. Burgarella ◽  
...  
Keyword(s):  
Gamma Ray ◽  
High Redshift ◽  
High Sensitivity ◽  
Infrared Light ◽  
Wide Field ◽  
Atmospheric Conditions ◽  
Large Area ◽  
Optical Telescope ◽  
Infrared Telescope ◽  
Scientific Potential

AbstractPILOT (the Pathfinder for an International Large Optical Telescope) is a proposed 2.5-m optical/infrared telescope to be located at Dome C on the Antarctic plateau. The atmospheric conditions at Dome C deliver a high sensitivity, high photometric precision, wide-field, high spatial resolution, and high-cadence imaging capability to the PILOT telescope. These capabilities enable a unique scientific potential for PILOT, which is addressed in this series of papers. The current paper presents a series of projects dealing with the distant (redshift >1) Universe, that have been identified as key science drivers for the PILOT facility. The potential for PILOT to detect the first populations of stars to form in the early Universe, via infrared projects searching for pair-instability supernovae and gamma-ray burst afterglows, is investigated. Two projects are proposed to examine the assembly and evolution of structure in the Universe: an infrared survey searching for the first evolved galaxies at high redshift, and an optical survey aimed at characterising moderate-redshift galaxy clusters. Finally, a large-area weak-lensing survey and a program to obtain supernova infrared light-curves are proposed to examine the nature and evolution of dark energy and dark matter.

scholarly journals The Science Case for PILOT III: the Nearby Universe

2009 ◽  
Vol 26 (4) ◽  
pp. 415-438 ◽  
Author(s):  
J. S. Lawrence ◽  
M. C. B. Ashley ◽  
J. Bailey ◽  
D. Barrado y Navascues ◽  
T. R. Bedding ◽  
...  
Keyword(s):  
Near Infrared ◽  
Monitoring Program ◽  
High Sensitivity ◽  
Low Earth Orbit ◽  
Infrared Light ◽  
Small Scale ◽  
Wide Field ◽  
Atmospheric Conditions ◽  
Optical Telescope ◽  
Infrared Telescope

AbstractPILOT (the Pathfinder for an International Large Optical Telescope) is a proposed 2.5-m optical/infrared telescope to be located at Dome C on the Antarctic plateau. The atmospheric conditions at Dome C deliver a high sensitivity, high photometric precision, wide-field, high spatial resolution, and high-cadence imaging capability to the PILOT telescope. These capabilities enable a unique scientific potential for PILOT, which is addressed in this series of papers. The current paper presents a series of projects dealing with the nearby Universe that have been identified as key science drivers for the PILOT facility. Several projects are proposed that examine stellar populations in nearby galaxies and stellar clusters in order to gain insight into the formation and evolution processes of galaxies and stars. A series of projects will investigate the molecular phase of the Galaxy and explore the ecology of star formation, and investigate the formation processes of stellar and planetary systems. Three projects in the field of exoplanet science are proposed: a search for free-floating low-mass planets and dwarfs, a program of follow-up observations of gravitational microlensing events, and a study of infrared light-curves for previously discovered exoplanets. Three projects are also proposed in the field of planetary and space science: optical and near-infrared studies aimed at characterising planetary atmospheres, a study of coronal mass ejections from the Sun, and a monitoring program searching for small-scale Low Earth Orbit satellite debris items.

scholarly journals FRAM—The Robotic Telescope for the Monitoring of the Wavelength Dependence of the Extinction: Description of Hardware, Data Analysis, and Results

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Michael Prouza ◽  
Martin Jelínek ◽  
Petr Kubánek ◽  
Jan Ebr ◽  
Petr Trávníček ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Ccd Camera ◽  
Cosmic Ray ◽  
Wavelength Dependence ◽  
Light Extinction ◽  
Wide Field ◽  
Atmospheric Conditions ◽  
Optical Telescope ◽  
Rapid Monitoring ◽  
Robotic Telescope

FRAM—F/(Ph)otometric Robotic Atmospheric Monitor is one of the atmospheric monitoring instruments at the Pierre Auger Observatory in Argentina. FRAM is an optical telescope equipped with CCD cameras and photometer, and it automatically observes a set of selected standard stars. Primarily, FRAM observations are used to obtain the wavelength dependence of the light extinction. FRAM telescope is also able to observe secondary astronomical targets, and namely the detection of optical counterparts of gamma-ray bursts has already proven to be successful. Finally, a wide-field CCD camera of FRAM can be used for rapid monitoring of atmospheric conditions along the track of particularly interesting cosmic ray showers. The hardware setup of the telescope, its software system, data taking procedures, and results of analysis are described in this paper.

scholarly journals Optical characterization of WISE selected blazar candidates

2019 ◽  
Vol 630 ◽  
pp. A55 ◽  
Author(s):  
Raniere de Menezes ◽  
Harold A. Peña-Herazo ◽  
Ezequiel J. Marchesini ◽  
Raffaele D’Abrusco ◽  
Nicola Masetti ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Optical Spectra ◽  
Sloan Digital Sky Survey ◽  
Wide Field ◽  
Large Area ◽  
Bl Lac Objects ◽  
True Nature ◽  
Normal Galaxies ◽  
Data Release ◽  
The Impact

Context. Over the last decade more than five thousand γ-ray sources have been detected by the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope. Given the positional uncertainty of the telescope, nearly 30% of these sources remain without an obvious counterpart at lower energies. This has motivated the release of new catalogs of γ-ray counterpart candidates and several follow up campaigns in the last decade. Aims. Recently, two new catalogs of blazar candidates were released. These are the improved and expanded version of the WISE Blazar-Like Radio-Loud Sources (WIBRaLS2) catalog and the Kernel Density Estimation selected candidate BL Lacs (KDEBLLACS) catalog, both selecting blazar-like sources based on their infrared colors from the Wide-field Infrared Survey Explorer (WISE). In this work we characterize these two catalogs, clarifying the true nature of their sources based on their optical spectra from SDSS data release 15, thus testing their efficiency in selecting true blazars. Methods. We first selected all WIBRaLS2 and KDEBLLACS sources with available optical spectra in the footprint of Sloan Digital Sky Survey data release 15. We then analyzed these spectra to verify the nature of each selected candidate and to measure the fraction of the catalogs composed by spectroscopically confirmed blazars. Finally, we evaluated the impact of selection effects, especially those related to optical colors of WIBRaLS2/KDEBLLACS sources and their optical magnitude distributions. Results. We found that at least ∼30% of each catalog is made up of confirmed blazars, with quasars being the major contaminants in the case of WIBRaLS2 (≈58%) and normal galaxies in the case of KDEBLLACS (≈38.2%). The spectral analysis also allowed us to identify the nature of 11 blazar candidates of uncertain type (BCUs) from the Fermi-LAT fourth Point Source Catalog (4FGL) and to find 25 new BL Lac objects.

scholarly journals Fermi: Monitoring the Gamma-Ray Universe

Galaxies ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 117 ◽  
Author(s):  
David Thompson
Keyword(s):  
Response Time ◽  
Real Time ◽  
Gamma Ray ◽  
High Redshift ◽  
Large Area ◽  
Long Duration ◽  
Level Data ◽  
High Level ◽  
Atmospheric Phenomena ◽  
Scientific Return

Since 2008, the Large Area Telescope and the Gamma-ray Burst Monitor on the Fermi Gamma-ray Space Telescope have been monitoring the entire sky at energies from about 8 keV to more than 1 TeV. Photon-level data and high-level data products are made publicly available in near-real time, and efforts continue to improve the response time. This long-duration, all-sky monitoring has enabled a broad range of science, from atmospheric phenomena on Earth to signals from high-redshift sources. The Fermi instrument teams have worked closely with multiwavelength and multi-messenger observers and theorists to maximize the scientific return from the observatory, and they look forward to continued cooperative efforts as Fermi moves into its second decade of operation.

scholarly journals Gamma-Ray Orbital Modulation of the Transitioning Millisecond Pulsar Binary XSS J12270–4859

2022 ◽  
Vol 924 (2) ◽  
pp. 91
Author(s):  
Hongjun An
Keyword(s):  
Gamma Ray ◽  
Optical Data ◽  
Large Area ◽  
Time Intervals ◽  
Optical Telescope ◽  
X Ray ◽  
Low Mass ◽  
Orbital Modulation ◽  
Short Time

Abstract We report on gamma-ray orbital modulation of the transitioning MSP binary XSS J12270–4859 detected in the Fermi Large Area Telescope (LAT) data. We use long-term optical data taken with the XMM-Newton OM and the Swift UltraViolet Optical Telescope to inspect radio timing solutions that are limited to relatively short time intervals and find that extrapolation of the solutions aligns well with the phasing of the optical data over 15 yr. The Fermi-LAT data folded on the timing solutions exhibit significant modulation (p = 5 × 10−6) with a gamma-ray minimum at the inferior conjunction of the pulsar. Intriguingly, the source seems to show similar modulation in both the low-mass X-ray binary and the MSP states, implying that mechanisms for gamma-ray emission in the two states are similar. We discuss these findings and their implications using an intrabinary shock scenario.

scholarly journals Radio VLBA polarization and multiband monitoring of the high-redshift quasar S5 0836 + 710 during a high-activity period

2019 ◽  
Vol 491 (1) ◽  
pp. 858-873 ◽  
Author(s):  
M Orienti ◽  
F D’Ammando ◽  
M Giroletti ◽  
D Dallacasa ◽  
G Giovannini ◽  
...  
Keyword(s):  
High Activity ◽  
Gamma Ray ◽  
High Redshift ◽  
Activity Period ◽  
X Rays ◽  
Large Area ◽  
The Core ◽  
Rotation Measure ◽  
Spectrum Radio ◽  
Γ Ray

ABSTRACT We report on results of a multiband monitoring campaign from radio to γ-rays of the high-redshift flat spectrum radio quasar S5 0836 + 710 during a high-activity period detected by the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. Two major flares were detected, in 2015 August and November. In both episodes, the apparent isotropic γ-ray luminosity exceeds 1050 erg s−1, with a doubling time-scale of about 3 h. The high γ-ray activity may be related to a superluminal knot that emerged from the core in 2015 April at the peak of the radio activity and is moving downstream along the jet. The low variability observed in X-rays may indicate that X-ray emission is produced by the low-energy tail of the same electron population that produces the γ-ray emission. The analysis of full-polarization pc-scale radio observations suggests the presence of a limb-brightened polarization structure at about 1 mas from the core in which a rotation measure gradient with a sign change is observed transverse to the jet direction. These characteristics are consistent with a scenario in which Faraday rotation is produced by a sheath of thermal electrons with a toroidal magnetic field surrounding the emitting jet.

scholarly journals THE CHANGING EVENT SURVEY: TRANSIENTS, SPACE DEBRIS & NEOs

2021 ◽  
Vol 53 ◽  
pp. 166-168
Author(s):  
T. Sun ◽  
C. Zhang ◽  
Y. Ping ◽  
X. Wu
Keyword(s):  
Space Debris ◽  
Gamma Ray ◽  
Variable Stars ◽  
Dual Band ◽  
Wide Field ◽  
Optical Telescope ◽  
Telescope Array ◽  
Near Earth Objects ◽  
Candidate Identification

Motivated by the promising era of time-domain and multi-messenger astronomy, CHanging Event Survey (CHES) is designed to join the ongoing campaign with a powerful wide-field optical telescope array. CHES project aims to monitor the transient universe, including gamma-ray bursts, fast radio bursts, the electromagnetic counterpart of gravitational waves events (kilonova), supernova, variable stars, near-earth objects, and space debris. The array consists of 12 individual wide field refractors with aperture 280 mm, covering 600 square degrees in total. In the same project, two 800 mm prime focus telescopes can be triggered for follow-up observation. Furthermore, CHES can effectively monitor 300 square deg in a dual band simultaneously, which enable the array to do candidate identification and follow-up for the triggers from LIGO/Virgo collaboration, Fermi, Swift, GECam and SVOM satellites.

scholarly journals The near and mid-infrared photometric properties of known redshift z ≥ 5 quasars

2020 ◽  
Vol 494 (1) ◽  
pp. 789-803 ◽  
Author(s):  
Nicholas P Ross ◽  
Nicholas J G Cross
Keyword(s):  
Near Infrared ◽  
Signal To Noise Ratio ◽  
High Redshift ◽  
Infrared Camera ◽  
Sloan Digital Sky Survey ◽  
Wide Field ◽  
Photometric Variability ◽  
Infrared Telescope ◽  
Black Hole Accretion ◽  
Very High

ABSTRACT We assemble a catalogue of 488 spectroscopically confirmed very high (z ≥ 5.00) redshift quasars (VHzQ) and report their near- (ZYJHKs/K) and mid- (WISE W1234) infrared properties. 97 per cent of the VHzQ sample is detected in one or more near-infrared (NIR) band, with lack of coverage rather than lack of depth being the reason for the non-detections. 389 (80 per cent) of the very high redshift quasars are detected at 3.4 μm in the W1 band from the unWISE catalogue and all of the z ≥ 7 quasars are detected in both unWISE W1 and W2. Using archival Wide Field Camera (WFCAM)/United Kingdom Infrared Telescope (UKIRT) and VISTA Infrared Camera (VIRCAM)/Visible and Infrared Survey Telescope for Astronomy (VISTA) data we check for photometric variability that might be expected from super-Eddington accretion. We find 28 of the quasars have sufficient NIR measurements and signal-to-noise ratio to look for variability. Weak variability was detected in multiple bands of Sloan Digital Sky Survey (SDSS) J0959+0227, and very marginally in the Y-band of MMT J0215-0529. Only one quasar, SDSS J0349+0034, shows significant differences between WFCAM and VISTA magnitudes in one band. With supermassive black hole accretion likely to be redshift invariant up to very high redshift, further monitoring of these sources is warranted. All the data, analysis codes and plots used and generated here can be found at: github.com/d80b2t/VHzQ.

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