First NuSTAR Observations of Mrk 501 within a Radio to TeV Multi-Instrument Campaign
Loading...
Access rights
openAccess
publishedVersion
URL
Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
This publication is imported from Aalto University research portal.
View publication in the Research portal (opens in new window)
View/Open full text file from the Research portal (opens in new window)
Other link related to publication (opens in new window)
View publication in the Research portal (opens in new window)
View/Open full text file from the Research portal (opens in new window)
Other link related to publication (opens in new window)
Date
2015-10
Major/Subject
Mcode
Degree programme
Language
en
Pages
Series
The Astrophysical Journal, Volume 812, issue 1, pp. 65
Abstract
We report on simultaneous broadband observations of the TeV-emitting blazar Markarian 501 between 2013 April 1 and August 10, including the first detailed characterization of the synchrotron peak with Swift and NuSTAR. During the campaign, the nearby BL Lac object was observed in both a quiescent and an elevated state. The broadband campaign includes observations with NuSTAR, MAGIC, VERITAS, the Fermi Large Area Telescope, Swift X-ray Telescope and UV Optical Telescope, various ground-based optical instruments, including the GASP-WEBT program, aswell as radio observations by OVRO, Metsähovi, and the F-Gamma consortium. Some of the MAGIC observations were affected by a sand layer from the Saharan desert, and had to be corrected using event-by-event corrections derived with a Light Detection and Ranging (LIDAR) facility.This is the first time that LIDAR information is used to produce a physics result with Cherenkov Telescope data taken during adverse atmospheric conditions, and hence sets a precedent for the current andfuture ground-based gamma-ray instruments. The NuSTAR instrument provides unprecedented sensitivity in hard X-rays, showing the source to display a spectral energy distribution (SED) between 3 and 79 keV consistent with a log-parabolic spectrum and hard X-ray variability onhour timescales. None (of the four extended NuSTAR observations) show evidence of the onset of inverse-Compton emission at hard X-ray energies. We apply a single-zone equilibrium synchrotron self-Compton(SSC) model to five simultaneous broadband SEDs. We find that the SSC model can reproduce the observed broadband states through a decrease inthe magnetic field strength coinciding with an increase in the luminosity and hardness of the relativistic leptons responsible for the high-energy emission.Description
VK: BIBCODE: 2015ApJ...812...65F; DOI: 10.1088/0004-637X/812/1/65; eprintid: arXiv:1509.04936
Keywords
BL Lacertae objects: general, galaxies: individual: Markarian 501, X-rays: galaxies
Other note
Citation
NuSTAR Team, MAGIC Collaboration & VERITAS Collaboration 2015, ' First NuSTAR Observations of Mrk 501 within a Radio to TeV Multi-Instrument Campaign ', The Astrophysical Journal, vol. 812, no. 1, pp. 65 . https://doi.org/10.1088/0004-637X/812/1/65