Journal article
The 2009 multiwavelength campaign on mrk 421: variability and correlation studies
Astronomy & Astrophysics
01 Apr 2015
Featured in Collection : UN Sustainable Development Goals @ Drexel
Abstract
Aims. We perform an extensive characterization of the broadband emission of Mrk 421, as well as its temporal evolution, during the non-flaring (low) state. The high brightness and nearby location (z = 0.031) of Mrk 421 make it an excellent laboratory to study blazar emission. The goal is to learn about the physical processes responsible for the typical emission of Mrk 421, which might also be extended to other blazars that are located farther away and hence are more difficult to study.
Methods. We performed a 4.5-month multi-instrument campaign on Mrk 421 between January 2009 and June 2009, which included VLBA, F-GAMMA, GASP-WEBT, Swift, RXTE, Fermi-LAT, MAGIC, and Whipple, among other instruments and collaborations. This extensive radio to very-high-energy (VHE; E > 100 GeV) gamma-ray dataset provides excellent temporal and energy coverage, which allows detailed studies of the evolution of the broadband spectral energy distribution.
Results. Mrk421 was found in its typical (non-flaring) activity state, with a VHE flux of about half that of the Crab Nebula, yet the light curves show significant variability at all wavelengths, the highest variability being in the X-rays. We determined the power spectral densities (PSD) at most wavelengths and found that all PSDs can be described by power-laws without a break, and with indices consistent with pink/red-noise behavior. We observed a harder-when-brighter behavior in the X-ray spectra and measured a positive correlation between VHE and X-ray fluxes with zero time lag. Such characteristics have been reported many times during flaring activity, but here they are reported for the first time in the non-flaring state. We also observed an overall anti-correlation between optical /UV and X-rays extending over the duration of the campaign.
Conclusions. The harder-when-brighter behavior in the X-ray spectra and the measured positive X-ray/VHE correlation during the 2009 multiwavelength campaign suggests that the physical processes dominating the emission during non-flaring states have similarities with those occurring during flaring activity. In particular, this observation supports leptonic scenarios as being responsible for the emission of Mrk 421 during non-flaring activity. Such a temporally extended X-ray /VHE correlation is not driven by any single flaring event, and hence is difficult to explain within the standard hadronic scenarios. The highest variability is observed in the X-ray band, which, within the one-zone synchrotron self-Compton scenario, indicates that the electron energy distribution is most variable at the highest energies.
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Details
- Title
- The 2009 multiwavelength campaign on mrk 421: variability and correlation studies
- Creators
- J Aleksić - Institute for High Energy PhysicsS Ansoldi - University of UdineL. A Antonelli - National Institute for AstrophysicsP Antoranz - University of SienaA Babic - University of SplitP Bangale - Max Planck SocietyU Barres de AlmeidaJ. A Barrio - Complutense University of MadridJ Becerra GonzálezW Bednarek - University of ŁódźK BergerE BernardiniA Biland - ETH ZurichO Blanch - Institute for High Energy PhysicsR. K Bock - Max Planck SocietyS Bonnefoy - Complutense University of MadridG Bonnoli - National Institute for AstrophysicsF Borracci - Max Planck SocietyT Bretz - École Polytechnique Fédérale de LausanneE CarmonaA Carosi - National Institute for AstrophysicsD Carreto FidalgoP Colin - Max Planck SocietyE ColomboJ. L Contreras - Complutense University of MadridJ Cortina - Institute for High Energy PhysicsS Covino - National Institute for AstrophysicsP Da Vela - University of SienaF Dazzi - University of UdineA De Angelis - University of UdineG De CanevaB De Lotto - University of UdineC Delgado MendezM Doert - TU Dortmund UniversityA Domínguez - University of California, RiversideD Dominis PresterD Dorner - University of WürzburgM Doro - University of PaduaS Einecke - TU Dortmund UniversityD Eisenacher - University of WürzburgD Elsaesser - University of WürzburgE Farina - University of InsubriaD Ferenc - University of SplitM. V Fonseca - Complutense University of MadridL Font - Autonomous University of BarcelonaK Frantzen - TU Dortmund UniversityC Fruck - Max Planck SocietyR. J García LópezM GarczarczykD Garrido TerratsM Gaug - Autonomous University of BarcelonaG Giavitto - Institute for High Energy PhysicsN Godinović - University of SplitA González MuñozS. R GozziniA Hadamek - TU Dortmund UniversityD Hadasch - Spanish National Research CouncilA HerreroD Hildebrand - ETH ZurichJ Hose - Max Planck SocietyD Hrupec - University of SplitW Idec - University of ŁódźV Kadenius - University of TurkuH Kellermann - Max Planck SocietyM. L Knoetig - ETH ZurichJ Krause - Max Planck SocietyJ Kushida - Kyoto UniversityA La Barbera - National Institute for AstrophysicsD Lelas - University of SplitN Lewandowska - University of WürzburgE LindforsF Longo - University of UdineS Lombardi - National Institute for AstrophysicsM López - Complutense University of MadridR López-Coto - Institute for High Energy PhysicsA López-Oramas - Institute for High Energy PhysicsE Lorenz - Max Planck SocietyI Lozano - Complutense University of MadridM Makariev - Bulgarian Academy of SciencesK MallotG Maneva - Bulgarian Academy of SciencesN Mankuzhiyil - University of UdineK Mannheim - University of WürzburgL Maraschi - National Institute for AstrophysicsB Marcote - University of BarcelonaM Mariotti - University of PaduaM Martínez - Institute for High Energy PhysicsD Mazin - Max Planck SocietyU Menzel - Max Planck SocietyM Meucci - University of SienaJ. M Miranda - University of SienaR Mirzoyan - Max Planck SocietyA Moralejo - Institute for High Energy PhysicsP Munar-Adrover - University of BarcelonaD Nakajima - Kyoto UniversityA Niedzwiecki - University of ŁódźK NilssonN Nowak - Stockholm UniversityR Orito - Kyoto UniversityA Overkemping - TU Dortmund UniversityS Paiano - University of PaduaM Palatiello - University of UdineD Paneque - Max Planck SocietyR Paoletti - University of SienaJ. M Paredes - University of BarcelonaX Paredes-Fortuny - University of BarcelonaS Partini - University of SienaM Persic - University of UdineF Prada - Spanish National Research CouncilP. G Prada MoroniE Prandini - University of PaduaS Preziuso - University of SienaI Puljak - University of SplitR Reinthal - University of TurkuW Rhode - TU Dortmund UniversityM Ribó - University of BarcelonaJ Rico - Institute for High Energy PhysicsJ RodriguezGarcia - Max Planck SocietyS Rügamer - University of WürzburgA Saggion - University of PaduaK Saito - Kyoto UniversityM Salvati - National Institute for AstrophysicsK Satalecka - Complutense University of MadridV Scalzotto - University of PaduaV Scapin - Complutense University of MadridC Schultz - University of PaduaT SchweizerS. N Shore - University of PisaA Sillanpää - University of TurkuJ Sitarek - Max Planck SocietyI Snidaric - University of SplitD Sobczynska - University of ŁódźF Spanier - University of WürzburgV Stamatescu - Institute for High Energy PhysicsA Stamerra - National Institute for AstrophysicsT Steinbring - University of WürzburgJ Storz - University of WürzburgS Sun - Max Planck SocietyT Surić - University of SplitL Takalo - University of TurkuF Tavecchio - National Institute for AstrophysicsP Temnikov - Bulgarian Academy of SciencesT Terzić - University of SplitD TescaroM Teshima - Max Planck SocietyJ Thaele - TU Dortmund UniversityO Tibolla - University of WürzburgD. F Torres - Spanish National Research CouncilT Toyama - Max Planck SocietyA Treves - University of InsubriaM Uellenbeck - TU Dortmund UniversityP Vogler - ETH ZurichR. M Wagner - Stockholm UniversityF Zandanel - University of AmsterdamR Zanin - University of BarcelonaS Archambault - McGill UniversityB BeheraM Beilicke - Washington University in St. LouisW Benbow - Harvard UniversityR Bird - University College DublinJ. H Buckley - Washington University in St. LouisV Bugaev - Washington University in St. LouisM Cerruti - Harvard UniversityX Chen - University of PotsdamL Ciupik - Adler PlanetariumE Collins-Hughes - University College DublinW Cui - Purdue University West LafayetteJ Dumm - University of MinnesotaJ. D Eisch - Iowa State UniversityA Falcone - Pennsylvania State UniversityS Federici - University of PotsdamQ Feng - Purdue University West LafayetteJ. P Finley - Purdue University West LafayetteH FleischhackP Fortin - Harvard UniversityL Fortson - University of MinnesotaA Furniss - University of California, Santa CruzS Griffin - McGill UniversityS. T Griffiths - University of IowaJ Grube - Adler PlanetariumG Gyuk - Adler PlanetariumD Hanna - McGill UniversityJ Holder - University of DelawareG HughesT. B Humensky - Columbia UniversityC. A Johnson - University of California, Santa CruzP Kaaret - University of IowaM Kertzman - DePauw UniversityY Khassen - University College DublinD Kieda - University of UtahH Krawczynski - Washington University in St. LouisF Krennrich - Iowa State UniversityS Kumar - University of DelawareM. J Lang - National University of Ireland, GalwayG MaierS McArthur - University of ChicagoK Meagher - Georgia Institute of TechnologyP Moriarty - Galway-Mayo Institute of TechnologyR Mukherjee - Columbia UniversityR. A Ong - University of California, Los AngelesA. N Otte - Georgia Institute of TechnologyN Park - University of ChicagoA Pichel - University of Buenos AiresM Pohl - University of PotsdamA Popkow - University of California, Los AngelesH ProkophJ Quinn - University College DublinK Ragan - McGill UniversityJ Rajotte - McGill UniversityP. T Reynolds - Cork Institute of TechnologyG. T Richards - Georgia Institute of TechnologyE Roache - Harvard UniversityA. C Rovero - University of Buenos AiresG. H Sembroski - Purdue University West LafayetteK Shahinyan - University of MinnesotaD Staszak - McGill UniversityI Telezhinsky - University of PotsdamM Theiling - Purdue University West LafayetteJ. V Tucci - Purdue University West LafayetteJ Tyler - Washington University in St. LouisA Varlotta - Purdue University West LafayetteS. P Wakely - University of ChicagoT. C Weekes - Harvard UniversityA WeinsteinR WelsingA Wilhelm - University of PotsdamD. A Williams - University of California, Santa CruzB Zitzer - Argonne National LaboratoryM VillataC RaiteriH. D Aller - University of Michigan–Ann ArborM. F Aller - University of Michigan–Ann ArborW. P Chen - National Central UniversityB Jordan - Dublin Institute For Advanced StudiesE Koptelova - Lomonosov Moscow State UniversityO. M Kurtanidze - Heidelberg UniversityA Lähteenmäki - Aalto UniversityB McBreen - University College DublinV. M Larionov - St Petersburg UniversityC. S Lin - National Central UniversityM. G NikolashviliE Angelakis - Max Planck SocietyM Capalbi - Instituto Politécnico NacionalA Carramiñana - National Institute of Astrophysics, Optics and ElectronicsL Carrasco - National Institute of Astrophysics, Optics and ElectronicsP Cassaro - National Institute for AstrophysicsA Cesarini - University of TrentoL Fuhrmann - Max Planck SocietyM GirolettiT Hovatta - California Institute of TechnologyT. P Krichbaum - Max Planck SocietyH. A Krimm - Goddard Space Flight CenterW Max-Moerbeck - California Institute of TechnologyJ. W Moody - Brigham Young UniversityG Maccaferri - National Institute for AstrophysicsY Mori - Tokyo Institute of TechnologyI Nestoras - Max Planck SocietyA Orlati - National Institute for AstrophysicsC Pace - Indiana UniversityR Pearson - Brigham Young UniversityM Perri - Instituto Politécnico NacionalA. C. S Readhead - California Institute of TechnologyJ. L Richards - Purdue University West LafayetteA. C Sadun - University of Colorado BoulderT Sakamoto - Aoyama Gakuin UniversityJ Tammi - Aalto UniversityM Tornikoski - Aalto UniversityY Yatsu - Tokyo Institute of TechnologyA Zook - Pomona College
- Publication Details
- Astronomy & Astrophysics
- Publisher
- EDP Sciences
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- Physics
- Web of Science ID
- WOS:000357274600061
- Scopus ID
- 2-s2.0-84928410952
- Other Identifier
- 991019201496004721
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