The TeV emission of Ap Librae: a hadronic interpretation and prospects for CTA

Abstract

Ap Librae is one out of a handful of low-frequency peaked blazars to be detected at TeV $\gamma$-rays and the only one with an identified X-ray jet. Combined observations of Fermi-LAT at high energies (HE) and of H.E.S.S at very high energies (VHE) revealed a striking spectral property of Ap Librae; the presence of a broad high-energy component that extends more than nine orders of magnitude in energy and is, therefore, hard to be explained by the usual single-zone synchrotron self-Compton model. We show that the superposition of different emission components related to photohadronic interactions can explain the $\gamma$-ray emission of Ap Librae without invoking external radiation fields. We present two indicative model fits to the spectral energy distribution of Ap Librae where the VHE emission is assumed to originate from a compact, sub-pc scale region of the jet. A robust prediction of our model is VHE flux variability on timescales similar to those observed at X-rays and HE $\gamma$-rays, which can be further used to distinguish between a sub-pc or kpc scale origin of the TeV emission. We thus calculate the expected variability signatures at X-rays, HE and VHE $\gamma$-rays and show that quasi-simultaneous flares are expected, with larger amplitude flares appearing at $\gamma$-rays. We assess the detectability of VHE variability from Ap Librae with CTA, next generation of IACTs. We show that $\sim$hr timescale variability at $E_{\gamma }>0.1$ TeV could be detectable at high significance with shorter exposure times than current Cherenkov telescopes.

arXiv comment11 pages, 4 figures, submitted to MNRAS

References in corpus (67)

• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• On the Absorption of X-rays in the Interstellar Medium
• The Leiden/Argentine/Bonn (LAB) Survey of Galactic HI: Final data release of the combined LDS and IAR surveys with improved stray-radiation corrections
• Atomic Data for Astrophysics. II. New Analytic Fits for Photoionization Cross Sections of Atoms and Ions
• The 6dF Galaxy Survey: Final Redshift Release (DR3) and Southern Large-Scale Structures
• General Relativistic Magnetohydrodynamic Simulations of Magnetically Choked Accretion Flows around Black Holes
• The extragalactic optical-infrared background radiations, their time evolution and the cosmic photon-photon opacity
• Design Concepts for the Cherenkov Telescope Array
• Magnetically Arrested Disk: An Energetically Efficient Accretion Flow
• Leptonic and Hadronic Modeling of Fermi-Detected Blazars
• The Connection between X-ray- and Radio-Selected BL Lacertae Objects
• CRATES: An All-Sky Survey of Flat-Spectrum Radio Sources
• The power of blazar jets
• The power of relativistic jets is larger than the luminosity of their accretion disks
• MOJAVE. X. Parsec-Scale Jet Orientation Variations and Superluminal Motion in AGN
• The Maximum Energy of Accelerated Particles in Relativistic Collisionless Shocks
• The Australia Telescope 20 GHz Survey: The Source Catalogue
• Relativistic Jets Shine through Shocks or Magnetic Reconnection?
• The blazar sequence: a new perspective
• Teraelectronvolt Astronomy
• Planck Early Results. VII. The Early Release Compact Source Catalog
• Energy spectra of gamma-rays, electrons and neutrinos produced at interactions of relativistic protons with low energy radiation
• SMARTS optical and infrared monitoring of 12 gamma-ray bright blazars
• X-ray Emission from Extragalactic Jets
• A hadronic origin for ultra-high-frequency-peaked BL Lac objects
• MOJAVE XIII. Parsec-Scale AGN Jet Kinematics Analysis Based on 19 years of VLBA Observations at 15 GHz
• TeV BL Lac objects at the dawn of the Fermi era
• Simultaneous Planck, Swift, and Fermi observations of X-ray and gamma-ray selected blazars
• Planck 2013 results. XXVIII. The Planck Catalogue of Compact Sources
• Prograde and Retrograde Black Holes: Whose Jet is More Powerful?
• Photohadronic origin of $\gamma$-ray BL Lac emission: implications for IceCube neutrinos
• The Palermo Swift-BAT hard X-ray catalogue III. Results after 54 months of sky survey
• 1SXPS: A deep Swift X-ray Telescope point source catalog with light curves and spectra
• Modelling the TeV gamma-ray spectra of two low redshift AGNs: Mkn 501 and Mkn 421
• UHECRs from magnetic reconnection in relativistic jets
• Catalogs of Hot White Dwarfs in the Milky Way from GALEX's Ultraviolet Sky Surveys. Constraining Stellar Evolution
• Discovery of very high energy gamma-ray emission from the low-frequency peaked BL Lacertae object BL Lacertae
• Formation of hard very-high energy spectra of blazars in leptonic models
• Black Hole Masses and Host Galaxy Evolution of Radio-loud Active Galactic Nuclei
• A realistic assessment of the CTA sensitivity to dark matter annihilation
• Variable Gamma-ray Emission Induced by Ultra-High Energy Neutral Beams: Application to 4C +21.35
• The Palermo Swift-BAT Hard X-ray Catalogue. II- Results after 39 months of sky survey
• The time-dependent one-zone hadronic model - First principles
• Bethe-Heitler emission in BL Lacs: filling the gap between X-rays and $\gamma$-rays
• Multiwavelength observations of a TeV-Flare from W Comae
• Discovery of Very High Energy gamma-rays from the blazar S5 0716+714
• GammaLib and ctools: A software framework for the analysis of astronomical gamma-ray data
• Ruling out IC/CMB X-rays in PKS 0637-752 and the Implications for TeV Emission from Large-Scale Quasar Jets
• Synchrotron and inverse-Compton emission from blazar jets I: a uniform conical jet model
• The seven year Swift-XRT point source catalog (1SWXRT)
• BL Lacertae: complex spectral variability and rapid synchrotron flare detected with BeppoSAX
• Fermi Rules Out the IC/CMB Model for the Large Scale Jet X-ray Emission of 3C 273
• A combined radio and GeV gamma-ray view of the 2012 and 2013 flares of Mrk 421
• Time-dependent neutrino emission from Mrk 421 during flares and predictions for IceCube
• Linking radio and gamma ray emission in Ap Librae
• H.E.S.S and Fermi-LAT discovery of gamma rays from the blazar 1ES 1312-423
• The stellar content of low redshift BL Lac host galaxies from multicolour imaging
• Synchrotron and inverse-Compton emission from blazar jets - IV. BL Lac type blazars and the physical basis for the blazar sequence
• The extended jet of AP Librae: Origin of the very high-energy gamma-ray emission?
• The high-energy $\gamma$-ray emission of AP Librae
• Modelling the variability of 1ES1218+30.4
• Broad Ly alpha Emission from Three Nearby BL Lacertae Objects
• Discovery of an extended X-ray jet in AP Librae
• Time-dependent modelling of PKS 2155-304 in a low state
• From Radio to TeV: The surprising Spectral Energy Distribution of AP Librae
• An HST/COS Observation of Broad Ly$\alpha$ Emission and Associated Absorption Lines of the BL Lacertae Object H 2356-309

Cited by in corpus (21)

• Fermi non-detections of four X-ray jet sources and implications for the IC/CMB mechanism
• Leptohadronic Multimessenger Modeling of 324 Gamma-Ray Blazars
• Proton Synchrotron $\gamma$-rays and the Energy Crisis in Blazars
• Can we observe neutrino flares in coincidence with explosive transients?
• Hadronuclear interactions in the jet of low TeV luminosity AGN: Implications for the low-state very-high-energy gamma-ray emission
• Blazars at Very High Energies: Emission Modelling
• LeHaMoC: a versatile time-dependent lepto-hadronic modeling code for high-energy astrophysical sources
• VERITAS Discovery of VHE Emission from the Radio Galaxy 3C 264: A Multi-Wavelength Study
• A marginally fast-cooling proton-synchrotron model for prompt GRBs
• Detection of an optical/UV jet/counterjet and Multiple Spectral Components in M84
• Long-term multi-wavelength study of 1ES 0647+250
• A Multi-Wavelength Study of Multiple Spectral Component Jets in AGN: Testing the IC/CMB Model for the Large-Scale-Jet X-ray Emission
• Revisiting the proton synchrotron radiation in blazar jets: Possible contributions from X-ray to $\gamma$-ray bands
• Analysis of the H.E.S.S. public data release with ctools
• Circumnuclear Dust in AP Librae and the source of its VHE emission
• Hadronic signatures from magnetically dominated baryon-loaded AGN jets
• Constraints on Proton Synchrotron Origin of Very High Energy Gamma Rays from the Extended Jet of AP Librae
• Megaparsec-scale Radio Structure Associated with a Hybrid Blazar SBS B1646+499: Episodic Jet Activity with Precessing Axis
• Multi-wavelength study of OT 081: broadband modelling of a transitional blazar
• Determining the composition of radio plasma via circular polarization: the prospects of the Cygnus A hot spots
• Time-dependent modelling of short-term variability in the TeV-blazar VER J0521+211 during the major flare in 2020