| Title: |
First NuSTAR Observations of Mrk 501 within a Radio to TeV Multi-Instrument Campaign |
| Authors: |
NuSTAR Team; MAGIC Collaboration; VERITAS Collaboration; F-Gamma Consortium; Galindo Fernández, Daniel; Marcote Martin, Benito; Paredes i Poy, Josep Maria; Paredes Fortuny, Xavier; Ribó Gomis, Marc; Zanin, Roberta |
| Source: |
Articles publicats en revistes (Física Quàntica i Astrofísica) |
| Publisher Information: |
Institute of Physics (IOP) |
| Publication Year: |
2015 |
| Collection: |
Dipòsit Digital de la Universitat de Barcelona |
| Subject Terms: |
Galàxies; Raigs X; Galaxies; X-rays |
| Description: |
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, as well 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 and future 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 on hour 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 in the magnetic field strength coinciding with an increase in the luminosity and hardness of the relativistic leptons responsible for the high-energy emission. |
| Document Type: |
article in journal/newspaper |
| File Description: |
22 p.; application/pdf |
| Language: |
English |
| Relation: |
Reproducció del document publicat a: http://dx.doi.org/10.1088/0004-637X/812/1/65; Astrophysical Journal, 2015, vol. 812, num. 1; http://dx.doi.org/10.1088/0004-637X/812/1/65; https://hdl.handle.net/2445/96037; 657261 |
| Availability: |
https://hdl.handle.net/2445/96037 |
| Rights: |
(c) American Astronomical Society, 2015 ; info:eu-repo/semantics/openAccess |
| Accession Number: |
edsbas.28F713F3 |
| Database: |
BASE |