Related papers: On the redshift of TeV BL Lac objects

On the redshift of the blazar PKS0447-439

PKS0447-439 is one of the BL Lacertae objects that have been detected at very high energy. There has been a recent report of a lower limit of z>1.246 for the redshift of this blazar, challenging the current paradigm in which very…

Cosmology and Nongalactic Astrophysics · Physics 2012-08-16 Michele Fumagalli , Amy Furniss , John M. O'Meara , J. Xavier Prochaska , David A. Williams , Emanuele P. Farina

Very-high-energy gamma-ray emission from high-redshift blazars

We study the possible detection of and properties of very high-energy (VHE) gamma-ray emission (in the energy band above 100 GeV) from high redshift sources. We report on the detection of VHE gamma-ray flux from blazars with redshifts…

High Energy Astrophysical Phenomena · Physics 2015-08-20 A. Neronov , D. V. Semikoz , A. M. Taylor , Ie. Vovk

VERITAS Observations of Six Bright, Hard-Spectrum Fermi-LAT Blazars

We report on VERITAS very-high-energy (VHE; E>100 GeV) observations of six blazars selected from the Fermi Large Area Telescope First Source Catalog (1FGL). The gamma-ray emission from 1FGL sources was extrapolated up to the VHE band,…

High Energy Astrophysical Phenomena · Physics 2015-06-11 E. Aliu , S. Archambault , T. Arlen , T. Aune , M. Beilicke , W. Benbow , M. Bottcher , A. Bouvier , J. H. Buckley , V. Bugaev , A. Cesarini , L. Ciupik , E. Collins-Hughes , M. P. Connolly , W. Cui , R. Dickherber , C. Duke , J. Dumm , M. Errando , A. Falcone , S. Federici , Q. Feng , J. P. Finley , G. Finnegan , L. Fortson , A. Furniss , N. Galante , D. Gall , S. Godambe , S. Griffin , J. Grube , G. Gyuk , D. Hanna , J. Holder , H. Huan , P. Kaaret , N. Karlsson , Y. Khassen , D. Kieda , H. Krawczynski , F. Krennrich , K. Lee , A. S Madhavan , G. Maier , P. Majumdar , S. McArthur , A. McCann , P. Moriarty , R. Mukherjee , T. Nelson , A. O'Faolain de Bhroithe , R. A. Ong , M. Orr , A. N. Otte , N. Park , J. S. Perkins , A. Pichel , M. Pohl , H. Prokoph , J. Quinn , K. Ragan , L. C. Reyes , P. T. Reynolds , E. Roache , D. B. Saxon , G. H. Sembroski , D. Staszak , I. Telezhinsky , G. Tesic , M. Theiling , S. Thibadeau , K. Tsurusaki , A. Varlotta , V. V. Vassiliev , S. Vincent , M. Vivier , S. P. Wakely , T. C. Weekes , A. Weinstein , R. Welsing , D. A. Williams , B. Zitzer , P. Fortin , D. Horan , M. Fumagalli , K. Kaplan , J. X. Prochaska

New hard-TeV extreme blazars detected with the MAGIC telescopes

Extreme high-frequency peaked BL Lac objects (EHBLs) are blazars which exhibit extremely energetic synchrotron emission. They also feature non-thermal gamma-ray emission whose peak lies in the very high-energy (VHE, E > 100 GeV) range, and…

High Energy Astrophysical Phenomena · Physics 2020-08-21 MAGIC Collaboration , V. A. Acciari , S. Ansoldi , L. A. Antonelli , A. Arbet Engels , K. Asano , D. Baack , A. Babić , B. Banerjee , U. Barres de Almeida , J. A. Barrio , J. Becerra González , W. Bednarek , L. Bellizzi , E. Bernardini , A. Berti , J. Besenrieder , W. Bhattacharyya , C. Bigongiari , A. Biland , O. Blanch , G. Bonnoli , Ž. Bošnjak , G. Busetto , R. Carosi , G. Ceribella , M. Cerruti , Y. Chai , A. Chilingaryan , S. Cikota , S. M. Colak , U. Colin , E. Colombo , J. L. Contreras , J. Cortina , S. Covino , V. D'Elia , P. Da Vela , F. Dazzi , A. De Angelis , B. De Lotto , M. Delfino , J. Delgado , D. Depaoli , F. Di Pierro , L. Di Venere , E. Do Souto Espiñeira , D. Dominis Prester , A. Donini , D. Dorner , M. Doro , D. Elsaesser , V. Fallah Ramazani , A. Fattorini , G. Ferrara , D. Fidalgo , L. Foffano , M. V. Fonseca , L. Font , C. Fruck , S. Fukami , R. J. García López , M. Garczarczyk , S. Gasparyan , M. Gaug , N. Giglietto , F. Giordano , N. Godinović , D. Green , D. Guberman , D. Hadasch , A. Hahn , J. Herrera , J. Hoang , D. Hrupec , M. Hütten , T. Inada , S. Inoue , K. Ishio , Y. Iwamura , L. Jouvin , D. Kerszberg , H. Kubo , J. Kushida , A. Lamastra , D. Lelas , F. Leone , E. Lindfors , S. Lombardi , F. Longo , M. López , R. López-Coto , A. López-Oramas , S. Loporchio , B. Machado de Oliveira Fraga , C. Maggio , P. Majumdar , M. Makariev , M. Mallamaci , G. Maneva , M. Manganaro , K. Mannheim , L. Maraschi , M. Mariotti , M. Martínez , D. Mazin , S. Mićanović , D. Miceli , M. Minev , J. M. Miranda , R. Mirzoyan , E. Molina , A. Moralejo , D. Morcuende , V. Moreno , E. Moretti , P. Munar-Adrover , V. Neustroev , C. Nigro , K. Nilsson , D. Ninci , K. Nishijima , K. Noda , L. Nogués , S. Nozaki , S. Paiano , M. Palatiello , D. Paneque , R. Paoletti , J. M. Paredes , P. Peñil , M. Peresano , M. Persic , P. G. Prada Moroni , E. Prandini , I. Puljak , W. Rhode , M. Ribó , J. Rico , C. Righi , A. Rugliancich , L. Saha , N. Sahakyan , T. Saito , S. Sakurai , K. Satalecka , K. Schmidt , T. Schweizer , J. Sitarek , I. Šnidarić , D. Sobczynska , A. Somero , A. Stamerra , D. Strom , M. Strzys , Y. Suda , T. Surić , M. Takahashi , F. Tavecchio , P. Temnikov , T. Terzić , M. Teshima , N. Torres-Albà , L. Tosti , V. Vagelli , J. van Scherpenberg , G. Vanzo , M. Vazquez Acosta , C. F. Vigorito , V. Vitale , I. Vovk , M. Will , D. Zarić , C. Arcaro , A. Carosi , F. D'Ammando , F. Tombesi , A. Lohfink

Emission models and EBL as a tool to measure the redshift of BL Lac objects

We introduce a new method to determine the redshift of unknown-redshift BL Lac Objects. The method relies on simultaneous multi-wavelength (MWL) observations of BL Lac objects in optical, X-ray, HE (E>100 MeV) gamma-rays and VHE (E>100…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Nijil Mankuzhiyil , Stefano Ansoldi , Gessica De Caneva , Massimo Persic , Fabrizio Tavecchio

The host galaxy of the BL Lacertae object 1ES 0647+250 and its imaging redshift

Since no spectroscopic redshift is available for the remarkable BL Lac object 1ES 0647+250, we aim to derive an estimate of its distance from the properties of its host galaxy.We obtained a deep, high-resolution near-infrared H-band image…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 J. K. Kotilainen , T. Hyvönen , R. Falomo , A. Treves , M. Uslenghi

New High-z Fermi BL Lacs with the Photometric Dropout Technique

Determining redshifts for BL Lacertae (BL Lac) objects using the traditional spectroscopic method is challenging due to the absence of strong emission lines in their optical spectra. We employ the photometric dropout technique to determine…

High Energy Astrophysical Phenomena · Physics 2017-01-04 A. Kaur , A. Rau , M. Ajello , J. Greiner , D. H. Hartmann , V. S. Paliya , A. Dominguez , J. Bolmer , P. Schady

On the Redshifts of the BL Lac 3FGL J0909.0+2310 and its Close Companion

We report on the redshift of the BL Lac object 3FGL J0909.0+2310 based on observations obtained with the OSIRIS Multi Object Spectrograph (MOS) mounted on the 10.4-m Gran Telescopio Canarias. A redshift of 0.432+/-0.002 was obtained by the…

Astrophysics of Galaxies · Physics 2017-01-18 D. Rosa-Gonzalez , S. Coutiño de Leon , Y. D. Mayya , A. Carramiñana , I. Aretxaga , J. Becerra Gonzalez , A. Furniss , E. Terlevich , O. Vega , J. Mendez-Abreu , J. Leon Tavares , A. L. Longinotti , R. Terlevich

TeV-peaked candidate BL Lac objects

BL Lac objects can be extreme in two ways: with their synchrotron emission, peaking beyond 1 keV in their spectral energy distribution, or with their gamma-ray emission, peaking at multi-TeV energies up to and beyond 10-20 TeV, like 1ES…

High Energy Astrophysical Phenomena · Physics 2020-01-08 Luigi Costamante

Detection of Exceptional X-Ray Spectral Variability in the TeV BL Lac 1ES 2344+514

We present the results of six BeppoSAX observations of 1ES 2344+514, five of which were taken within a week. 1ES 2344+514, one of the few known TeV BL Lac objects, was detected by the BeppoSAX Narrow Field Instruments between 0.1 to \~50…

Astrophysics · Physics 2009-10-31 P. Giommi , P. Padovani , E. Perlman

Multi-wavelength observations of the TeV Blazars Mkn~421, 1ES1959+650, and H1426+428 with the HEGRA Cherenkov telescopes and the RXTE X-ray satellite

Recent results obtained with the HEGRA system of imaging Cherenkov telescopes on the TeV emission of the Blazars Mkn~421 ($z=0.030$), 1ES1959+650 ($z=0.047$), and H1426+428 ($z=0.129$) are reported. For Mkn~421, a close connection of the…

Astrophysics · Physics 2007-05-23 D. Horns , the HEGRA collaboration

MAGIC long-term study of the distant TeV blazar PKS 1424+240 in a multiwavelength context

We present a study of the very high energy (VHE; E > 100 GeV) gamma-ray emission of the blazar PKS 1424+240 observed with the MAGIC telescopes. The primary aim of this paper is the multiwavelength spectral characterization and modeling of…

High Energy Astrophysical Phenomena · Physics 2014-09-05 MAGIC Collaboration , J. Aleksić , S. Ansoldi , L. A. Antonelli , P. Antoranz , A. Babic , P. Bangale , U. Barres de Almeida , J. A. Barrio , J. Becerra González , W. Bednarek , E. Bernardini , A. Biland , O. Blanch , S. Bonnefoy , G. Bonnoli , F. Borracci , T. Bretz , E. Carmona , A. Carosi , D. Carreto Fidalgo , P. Colin , E. Colombo , J. L. Contreras , J. Cortina , S. Covino , P. Da Vela , F. Dazzi , A. De Angelis , G. De Caneva , B. De Lotto , C. Delgado Mendez , M. Doert , A. Domínguez , D. Dominis Prester , D. Dorner , M. Doro , S. Einecke , D. Eisenacher , D. Elsaesser , E. Farina , D. Ferenc , M. V. Fonseca , L. Font , K. Frantzen , C. Fruck , R. J. García López , M. Garczarczyk , D. Garrido Terrats , M. Gaug , N. Godinović , A. González Muñoz , S. R. Gozzini , D. Hadasch , M. Hayashida , J. Herrera , A. Herrero , D. Hildebrand , J. Hose , D. Hrupec , W. Idec , V. Kadenius , H. Kellermann , K. Kodani , Y. Konno , J. Krause , H. Kubo , J. Kushida , A. La Barbera , D. Lelas , N. Lewandowska , E. Lindfors , S. Lombardi , M. López , R. López-Coto , A. López-Oramas , E. Lorenz , I. Lozano , M. Makariev , K. Mallot , G. Maneva , N. Mankuzhiyil , K. Mannheim , L. Maraschi , B. Marcote , M. Mariotti , M. Martínez , D. Mazin , U. Menzel , M. Meucci , J. M. Miranda , R. Mirzoyan , A. Moralejo , P. Munar-Adrover , D. Nakajima , A. Niedzwiecki , K. Nilsson , K. Nishijima , K. Noda , N. Nowak , R. Orito , A. Overkemping , S. Paiano , M. Palatiello , D. Paneque , R. Paoletti , J. M. Paredes , X. Paredes-Fortuny , S. Partini , M. Persic , F. Prada , P. G. Prada Moroni , E. Prandini , S. Preziuso , I. Puljak , R. Reinthal , W. Rhode , M. Ribó , J. Rico , J. Rodriguez Garcia , S. Rügamer , A. Saggion , T. Saito , K. Saito , K. Satalecka , V. Scalzotto , V. Scapin , C. Schultz , T. Schweizer , S. N. Shore , A. Sillanpää , J. Sitarek , I. Snidaric , D. Sobczynska , F. Spanier , V. Stamatescu , A. Stamerra , T. Steinbring , J. Storz , S. Sun , T. Surić , L. Takalo , H. Takami , F. Tavecchio , P. Temnikov , T. Terzić , D. Tescaro , M. Teshima , J. Thaele , O. Tibolla , D. F. Torres , T. Toyama , A. Treves , M. Uellenbeck , P. Vogler , R. M. Wagner , F. Zandanel , R. Zanin , S. Cutini , D. Gasparrini , A. Furniss , T. Hovatta , T. Kangas , E. Kankare , J. Kotilainen , M. Lister , A. Lähteenmäki , W. Max-Moerbeck , V. Pavlidou , A. Readhead , J. Richards

Very high energy $\gamma$-ray emission from two blazars of unknown redshift and upper limits on their distance

We report on the detection of very-high-energy (VHE; $E > 100$ GeV) $\gamma$-ray emission from the BL Lac objects KUV 00311-1938 and PKS 1440-389 with the High Energy Stereoscopic System (H.E.S.S.). H.E.S.S. observations were accompanied or…

High Energy Astrophysical Phenomena · Physics 2020-04-29 H. E. S. S. Collaboration , H. Abdalla , R. Adam , F. Aharonian , F. Ait Benkhali , E. O. Angüner , M. Arakawa , C. Arcaro , C. Armand , T. Armstrong , H. Ashkar , M. Backes , V. Baghmanyan , V. Barbosa Martins , A. Barnacka , M. Barnard , Y. Becherini , D. Berge , K. Bernlöhr , M. Böttcher , C. Boisson , J. Bolmont , S. Bonnefoy , J. Bregeon , M. Breuhaus , F. Brun , P. Brun , M. Bryan , M. Büchele , T. Bulik , T. Bylund , S. Caroff , A. Carosi , S. Casanova , T. Chand , S. Chandra , A. Chen , G. Cotter , M. Curyło , I. D. Davids , J. Davies , C. Deil , J. Devin , P. deWilt , L. Dirson , A. Djannati-Ataï , A. Dmytriiev , A. Donath , V. Doroshenko , J. Dyks , K. Egberts , F. Eichhorn , G. Emery , J. -P. Ernenwein , K. Feijen , S. Fegan , A. Fiasson , G. Fontaine , S. Funk , M. Füßling , S. Gabici , Y. A. Gallant , G. Giavitto , L. Giunti , D. Glawion , J. F. Glicenstein , D. Gottschall , M. -H. Grondin , J. Hahn , M. Haupt , G. Hermann , J. A. Hinton , W. Hofmann , C. Hoischen , T. L. Holch , M. Holler , M. H{\"}orbe , D. Horns , D. Huber , H. Iwasaki , M. Jamrozy , D. Jankowsky , F. Jankowsky , A. Jardin-Blicq , V. Joshi , I. Jung-Richardt , M. A. Kastendieck , K. Katarzynski , M. Katsuragawa , U. Katz , D. Khangulyan , B. Khélifi , S. Klepser , W. Kluzniak , Nu. Komin , R. Konno , K. Kosack , D. Kostunin , M. Kreter , G. Lamanna , A. Lemière , M. Lemoine-Goumard , J. -P. Lenain , E. Leser , C. Levy , T. Lohse , I. Lypova , J. Mackey , J. Majumdar , D. Malyshev , D. Malyshev , V. Marandon , P. Marchegiani , A. Marcowith , A. Mares , G. Martí-Devesa , R. Marx , G. Maurin , P. J. Meintjes , R. Moderski , M. Mohamed , L. Mohrmann , C. Moore , P. Morris , E. Moulin , J. Muller , T. Murach , S. Nakashima , K. Nakashima , M. de Naurois , H. Ndiyavala , F. Niederwanger , J. Niemiec , L. Oakes , P. O'Brien , H. Odaka , S. Ohm , E. de Ona Wilhelmi , M. Ostrowski , M. Panter , R. D. Parsons , B. Peyaud , Q. Piel , S. Pita , V. Poireau , A. Priyana Noel , D. A. Prokhorov , H. Prokoph , G. Pühlhofer , M. Punch , A. Quirrenbach , S. Raab , R. Rauth , A. Reimer , O. Reimer , Q. Remy , M. Renaud , F. Rieger , L. Rinchiuso , C. Romoli , G. Rowell , B. Rudak , E. Ruiz-Velasco , V. Sahakian , S. Sailer , S. Saito , D. A. Sanchez , A. Santangelo , M. Sasaki , M. Scalici , F. Schüssler , H. M. Schutte , U. Schwanke , S. Schwemmer , M. Seglar-Arroyo , M. Senniappan , A. S. Seyffert , N. Shafi , K. Shiningayamwe , R. Simoni , A. Sinha , H. Sol , A. Specovius , S. Spencer , M. Spir-Jacob , Ł. Stawarz , R. Steenkamp , C. Stegmann , C. Steppa , T. Takahashi , T. Tavernier , A. M. Taylor , R. Terrier , D. Tiziani , M. Tluczykont , L. Tomankova , C. Trichard , M. Tsirou , N. Tsuji , R. Tuffs , Y. Uchiyama , D. J. van der Walt , C. van Eldik , C. van Rensburg , B. van Soelen , G. Vasileiadis , J. Veh , C. Venter , P. Vincent , J. Vink , H. J. Völk , T. Vuillaume , Z. Wadiasingh , S. J. Wagner , J. Watson , F. Werner , R. White , A. Wierzcholska , R. Yang , H. Yoneda , M. Zacharias , R. Zanin , D. Zargaryan , A. A. Zdziarski , A. Zech , S. J. Zhu , J. Zorn , N. Żywucka , M. Cerruti

Detection of the BL Lac Object H1426+428 at TeV Gamma Ray Energies

A very high energy (VHE) gamma-ray signal has been detected at the 5.4 sigma level from H1426+428, an x-ray selected BL Lacertae object at a redshift of 0.129. The object was monitored from 1995 - 1998 with the Whipple 10m imaging…

Astrophysics · Physics 2019-08-14 D. Horan

Changing Look of the optical spectrum of the MeV Blazar PKS 0446+112 (4FGL J0449.1+1121)

Following the high activity of the gamma-ray Fermi source 4FGL J0449.1+1121 (PKS 0446+112), possibly associated with a IceCube neutrino event IC-240105A, we obtained optical spectroscopy with the Gran Telescopio Canarias of the counterpart.…

High Energy Astrophysical Phenomena · Physics 2024-05-20 Simona Paiano , Renato Falomo , Aldo Treves , Riccardo Scarpa , Boris Sbarufatti

On the Redshift of the Very High Energy Blazar 3C 66A

As a bright gamma-ray source, 3C 66A is of great interest to the high-energy astrophysics community, having a potential for placing cosmological constraints on models for the extragalactic background light (EBL) and the processes which…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Amy Furniss , Michele Fumagalli , Charles Danforth , David A. Williams , Jason X. Prochaska

GeV-TeV $\gamma$-ray energy spectral break of BL Lac objects

In this paper, we compile the very-high-energy and high-energy spectral indices of 43 BL Lac objects from the literature. Based on a simple math model, $\Delta\Gamma_{obs}=\alpha {\rm{z}}+\beta $, we present evidence for the origin of an…

High Energy Astrophysical Phenomena · Physics 2018-08-08 W. Zhong , W. G. Liu , Y. G. Zheng

Comparison between TeV and non-TeV BL Lac Objects

BL Lacertae objects (BL Lacs) is the dominant population of TeV emitting blazars. In this work, we investigate whether there is any special observational properties for TeV sources. To do so, we will compare the observational properties of…

High Energy Astrophysical Phenomena · Physics 2016-07-13 C. Lin , J. H. Fan

VERITAS Observations of the BL Lac Object PG 1553+113 Between May 2010 and May 2011

VERITAS, an array of imaging atmospheric-Cherenkov telescopes, studies blazars in the energy range between ~100 GeV and ~30 TeV. With its excellent sensitivity at these energies, and ever-deepening source exposures, VERITAS is in a position…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-13 Matthew Orr

Estimation of the Extragalactic Background Light using TeV Observations of BL~Lacs

The very high energy (VHE) gamma ray spectral index of high energy peaked blazars correlates strongly with its corresponding redshift whereas no such correlation is observed in the X-ray or the GeV bands. We attribute this correlation to a…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Atreyee Sinha , Sunder Sahayanathan , Ranjeev Misra , Sagar Godambe , B. S. Acharya