Explanipedia

High energy gamma-ray sources in the VVV survey – III. Spectroscopic confirmation of an AGN at low Galactic latitudes Open

E. O. Schmidt, Laura D Baravalle, A. Pichel, D. Mast, M. V. Alonso , et al. · 2025

We aim to spectroscopically confirm the nature of VVV-J181258.71-314346.7, a candidate counterpart to the unassociated gamma-ray source 4FGLJ1812.8−3144. This object was selected based on its near-infrared photometric properties and modera…

The VVV near-IR galaxy catalogue of the southern Galactic disc Open

M. V. Alonso, Laura D Baravalle, J. L. Nilo Castellón, C. Villalón, M. Soto , et al. · 2025

Context. The distribution of galaxies in the zone of avoidance (ZoA) is incomplete due to the presence of our own Galaxy. Aims. Our research is focussed on the identification and characterisation of galaxies in the ZoA, using the new near-…

The VVV near-IR galaxy catalogue of the southern Galactic disc Open

M. V. Alonso, Laura D Baravalle, J. L. Nilo Castellón, C. Villalón, M. Soto , et al. · 2025

The distribution of galaxies in the Zone of Avoidance (ZoA) is incomplete due to the presence of our own Galaxy. Our research focused on the identification and characterisation of galaxies in the ZoA, using the new near-infrared data from …

High energy gamma-ray sources in the VVV survey -- II. The AGN counterparts Open

L. Donoso, A. Pichel, Laura D Baravalle, M. Victoria Alonso, E. O. Schmidt , et al. · 2024

We identified Active Galactic Nuclei (AGN) candidates as counterparts to unidentified gamma-ray sources (UGS) from the Fermi-LAT Fourth Source Catalogue at lower Galactic latitudes. Our methodology is based on the use of near- and mid-infr…

Statistical redshift of the very-high-energy blazar S5 0716+714 Open

A. Pichel, C. Donzelli, H. Muriel, Adrián Rovero, D. Rosa‐González , et al. · 2023

Context. Blazars are the most numerous class of very-high-energy (VHE; E > 100 GeV) gamma-ray emitters. At present, measured redshifts are available only for about 80% of the VHE gamma-ray sources; this is mainly due to the difficulty in m…

AGN candidates in the VVV near-IR galaxy catalogue Open

Laura D Baravalle, E. O. Schmidt, M. V. Alonso, A. Pichel, D. Minniti , et al. · 2023

The goal of this work is to search for Active Galactic Nuclei (AGN) in the Galactic disc at very low latitudes with |b| < 2°. For this, we studied the five sources from the VVV near-infrared (IR) galaxy catalogue that have also WISE cou…

AGN candidates in the VVV near-IR galaxy catalogue Open

Laura D Baravalle, E. O. Schmidt, M. Victoria Alonso, A. Pichel, D. Minniti , et al. · 2023

The goal of this work is to search for Active Galactic Nuclei (AGN) in the Galactic disc at very low latitudes with |b| $<$ 2$^\circ$. For this, we studied the five sources from the VVV near-infrared galaxy catalogue that have also WISE co…

VTSCat: The VERITAS Catalog of Gamma-Ray Observations Open

A. Acharyya, C. B. Adams, A. Archer, P. Bangale, J. T. Bartkoske , et al. · 2023

VTSCat is the catalog of high-level data products from all publications of the VERITAS collaboration. The VTSCat data collection contains: high-level data like spectral flux points, light curves, spectral fits in human and machine-readable…

VTSCat: The VERITAS Catalog of Gamma-Ray Observations Open

A. Acharyya, C. B. Adams, A. Archer, P. Bangale, J. T. Bartkoske , et al. · 2023

The ground-based gamma-ray observatory Very Energetic Radiation Imaging Telescope Array System (VERITAS, https://veritas.sao.arizona.edu/ ) is sensitive to photons of astrophysical origin with energies in the range between ≈85 GeV and ≈30 …

Observation of the Gamma-Ray Binary HESS J0632+057 with the H.E.S.S., MAGIC, and VERITAS Telescopes Open

C. B. Adams, W. Benbow, A. Brill, J. H. Buckley, M. Capasso , et al. · 2021

The results of gamma-ray observations of the binary system HESS J0632 + 057 collected during 450 hr over 15 yr, between 2004 and 2019, are presented. Data taken with the atmospheric Cherenkov telescopes H.E.S.S., MAGIC, and VERITAS at ener…

New Observations with Gemini and GTC of the VHE Blazar KUV 00311–1938: About Its Redshift and Environment Open

A. Pichel, C. Donzelli, D. Rosa‐González, M. Fernández Alonso, Adrián Rovero , et al. · 2020

Extragalactic very-high-energy (VHE; E > 100 GeV) sources are unique objects to study the most powerful particle accelerators in nature, as active galactic nuclei are likely sources of ultra-high-energy cosmic rays. BL Lacertae blazars are…

The Great Markarian 421 Flare of 2010 February: Multiwavelength Variability and Correlation Studies Open

A. U. Abeysekara, W. Benbow, R. Bird, A. Brill, Robert Brose , et al. · 2020

We report on variability and correlation studies using multiwavelength observations of the blazar Mrk 421 during the month of 2010 February, when an extraordinary flare reaching a level of ∼27 Crab Units above 1 TeV was measured in very hi…

Redshift of the Blazar KUV 00311-1938: Modeling the EBL Absorption Open

Mateo Fernandez Alonso, A. Pichel, Adrián Rovero · 2019

AGNs are believed to be the source of very energetic cosmic rays which, in turn, produce gamma rays throughout the interactions with matter. Therefore, the study of their very-high-energy (VHE) gamma-ray spectra is fundamental to understan…

Redshift of the Blazar KUV 00311-1938: Modeling the EBL Absorption Open

Mateo Fernandez Alonso, A. Pichel, Adrián Rovero · 2019

AGNs are believed to be the source of very energetic cosmic rays which, in turn, produce gamma rays throughout the interactions with matter. Therefore, the study of their very-high-energy (VHE) gamma-ray spectra is fundamental to understan…

The Southern Wide-Field Gamma-Ray Observatory (SWGO): A Next-Generation Ground-Based Survey Instrument for VHE Gamma-Ray Astronomy Open

P. Abreu, A. Albert, R. Alfaro, C. Álvarez, R. Arceo , et al. · 2019

We describe plans for the development of the Southern Wide-field Gamma-ray Observatory (SWGO), a next-generation instrument with sensitivity to the very-high-energy (VHE) band to be constructed in the Southern Hemisphere. SWGO will provide…

New GTC spectroscopic data and a statistical study to better constrain the redshift of the BL Lac RGB J2243 + 203 Open

D. Rosa‐González, H. Muriel, Y. D. Mayya, I. Aretxaga, J. Becerra González , et al. · 2018

We present new spectroscopic data of the BL Lac RGB 2243 + 203, and its surroundings, obtained with the OSIRIS Multi Object Spectrograph (MOS) mounted in the Gran Telescopio Canarias (GTC). The spectra of neither the BL Lac nor its host ga…

Very-High-Energy γ-Ray Observations of the Blazar 1ES 2344+514 with VERITAS Open

Cameron H. Allen, S. Archambault, A. Archer, W. Benbow, R. Bird , et al. · 2017

We present very-high-energy $\gamma$-ray observations of the BL Lac object 1ES 2344+514 taken by the Very Energetic Radiation Imaging Telescope Array System between 2007 and 2015. 1ES 2344+514 is detected with a statistical significance ab…

Redshift measurement of the BL-Lac gamma-ray blazar PKS 1424+240 Open

Adrián Rovero, C. Donzelli, A. Pichel, H. Muriel · 2016

PKS 1424+240 is a BL-Lac blazar with unknown redshift detected at high-energy gamma rays by Fermi-LAT with a hard spectrum.It was first detected at very-high-energy by VERITAS and latter confirmed by MAGIC.Attempts to find limits on its re…

UPPER LIMITS FROM FIVE YEARS OF BLAZAR OBSERVATIONS WITH THE VERITAS CHERENKOV TELESCOPES Open

S. Archambault, A. Archer, W. Benbow, R. Bird, J. Biteau , et al. · 2016

Between the beginning of its full-scale scientific operations in 2007 and 2012, the VERITAS Cherenkov telescope array observed more than 130 blazars; of these, 26 were detected as very-high-energy (VHE; E > 100 GeV) γ -ray sources. In this…

The BL-Lacertae gamma-ray blazar PKS 1424+240 associated with a group of galaxies at z = 0.6010 Open

Adrián Rovero, H. Muriel, C. Donzelli, A. Pichel · 2016

PKS 1424+240 is a BL-Lac blazar with unknown redshift that was detected at high-energy gamma rays by Fermi-LAT with a hard spectrum. At very high energy (VHE), it was first detected by VERITAS and later confirmed by MAGIC. Its spectral ene…

Redshift measurement of the BL-Lac gamma-ray blazar PKS 1424+240 Open

Adrián Rovero, C. Donzelli, A. Pichel, H. Muriel · 2015

PKS 1424+240 is a BL-Lac blazar with unknown redshift detected at high-energy gamma rays by Fermi-LAT with a hard spectrum. It was first detected at very-high-energy by VERITAS and latter confirmed by MAGIC. Attempts to find limits on its …

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