pith. sign in

arxiv: 2605.20153 · v2 · pith:5TBYW33Inew · submitted 2026-05-19 · 🌌 astro-ph.HE

The exceptional 2017 gamma-ray flare of the radio galaxy NGC 1275: VERITAS and Multiwavelength Observations

A. Acharyya , A. Archer , P. Bangale , J. T. Bartkoske , W. Benbow , Y. Chen , J. L. Christiansen , A. J. Chromey
show 61 more authors
A. Duerr M. Errando M. Escobar Godoy A. Falcone S. Feldman Q. Feng S. Filbert L. Fortson A. Furniss W. Hanlon O. Hervet C. E. Hinrichs J. Holder Z. Hughes M. Iskakova W. Jin M. N. Johnson P. Kaaret M. Kertzman M. Kherlakian D. Kieda T. K. Kleiner N. Korzoun F. Krennrich S. Kundu M. J. Lang M. Lundy G. Maier E. Meyer P. Moriarty R. Mukherjee W. Ning M. Ohishi R. A. Ong A. Pandey J. Escudero Pedrosa M. Pohl E. Pueschel J. Quinn P. L. Rabinowitz K. Ragan P. T. Reynolds D. Ribeiro E. Roache C. Rulten I. Sadeh L. Saha M. Santander G. H. Sembroski R. Shang M. Splettstoesser D. Tak A. K. Talluri J. V. Tucci J. Valverde V. V. Vassiliev D. A. Williams S. L. Wong T. Yoshikoshi P. S. Smith J. Kataoka
This is my paper

Pith reviewed 2026-06-30 17:55 UTC · model grok-4.3

classification 🌌 astro-ph.HE
keywords NGC 1275gamma-ray flareVERITASmultiwavelengthblob-in-jet modelradio galaxyC3 componentspectral energy distribution
0
0 comments X

The pith

Blob-in-jet modeling of NGC 1275's 2017 flare supports a two-component jet viewed at 10 degrees with gamma-ray emission near C3.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper presents VERITAS detection of the declining phase of an exceptional VHE flare from NGC 1275 in January 2017, combined with Fermi-LAT, MAGIC, and radio data spanning 2009-2017. Spectral energy distributions constructed for the nights of January 1 and 2 show a change from a power-law spectrum with exponential cutoff to a log-parabola, with an overall harder-when-brighter trend. Application of blob-in-jet modeling to these SEDs yields support for a two-component jet model oriented at 10 degrees to the line of sight, locating the gamma-ray emission region near the C3 radio component. A sympathetic reader cares because the result ties the variable high-energy output directly to a tracked radio structure inside the jet of this nearby active galaxy.

Core claim

The central claim is that blob-in-jet modeling of the multi-band SEDs for 2017 January 1 and 2 supports a two-component model with a jet angle of 10 degrees to the line of sight and the gamma-ray emission zone located in the vicinity of the C3 radio component.

What carries the argument

Blob-in-jet modeling of the two-night SEDs, which fits parameters including viewing angle and emission-zone location to the observed flux and spectral evolution.

If this is right

  • Gamma-ray emission during the flare originates near the C3 radio component.
  • The jet is viewed at approximately 10 degrees to the line of sight.
  • The observed spectral change from cutoff power law to log-parabola reflects evolution within the two-component structure.
  • The long-term harder-when-brighter behavior in VERITAS data is consistent with the same jet geometry.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Similar modeling applied to other radio galaxies could test whether 10-degree viewing angles commonly produce detectable VHE flares.
  • Repeated flares could allow tracking of whether the emission zone remains fixed relative to C3 or moves along the jet.
  • The intermediate viewing angle implied by the model offers a bridge between aligned blazars and misaligned radio galaxies for jet emission studies.

Load-bearing premise

The blob-in-jet model correctly describes the emission physics so that its parameters can be constrained by fitting the two-night SEDs.

What would settle it

An independent measurement, such as VLBI imaging or polarization data, showing the gamma-ray emission zone is far from C3 or the jet angle differs substantially from 10 degrees.

Figures

Figures reproduced from arXiv: 2605.20153 by A. Acharyya, A. Archer, A. Duerr, A. Falcone, A. Furniss, A. J. Chromey, A. K. Talluri, A. Pandey, C. E. Hinrichs, C. Rulten, D. A. Williams, D. Kieda, D. Ribeiro, D. Tak, E. Meyer, E. Pueschel, E. Roache, F. Krennrich, G. H. Sembroski, G. Maier, I. Sadeh, J. Escudero Pedrosa, J. Holder, J. Kataoka, J. L. Christiansen, J. Quinn, J. T. Bartkoske, J. Valverde, J. V. Tucci, K. Ragan, L. Fortson, L. Saha, M. Errando, M. Escobar Godoy, M. Iskakova, M. J. Lang, M. Kertzman, M. Kherlakian, M. Lundy, M. N. Johnson, M. Ohishi, M. Pohl, M. Santander, M. Splettstoesser, N. Korzoun, O. Hervet, P. Bangale, P. Kaaret, P. L. Rabinowitz, P. Moriarty, P. S. Smith, P. T. Reynolds, Q. Feng, R. A. Ong, R. Mukherjee, R. Shang, S. Feldman, S. Filbert, S. Kundu, S. L. Wong, T. K. Kleiner, T. Yoshikoshi, V. V. Vassiliev, W. Benbow, W. Hanlon, W. Jin, W. Ning, Y. Chen, Z. Hughes.

Figure 1
Figure 1. Figure 1: The daily-binned multiwavelength light curve of NGC 1275 for the VERITAS observing season 2016/17. The light curves include data recorded with VERITAS (first / top panel), MAGIC [MAGIC Collaboration et al. 2018] (second panel), Fermi-LAT (third panel), Swift-XRT (fourth panel), Swift-UVOT (fifth panel), Tuorla [MAGIC Collaboration et al. 2018] (sixth panel), Steward Optical Polarization percentage and Posi… view at source ↗
Figure 2
Figure 2. Figure 2: Top panel: long-term VERITAS TeV light curve for all 4-telescope observations of radio galaxy NGC 1275 for the energy range 0.15 TeV ⩽ E ⩽ 30 TeV, spanning more than 8-years (2009-2017) and binned in 28-day intervals. The median flux (solid orange line) and 1σ root mean squared deviation (RMSD; orange band) are shown, with 95% confidence-level upper limits plotted for flux points < 2σ. Center panel: averag… view at source ↗
Figure 3
Figure 3. Figure 3: The spectra calculated for the average low￾state (open blue circles), the average high-state (open orange squares) and for the extreme-high-state flares that occurred on MJD57755 (green-filled circles) and MJD57756 (purple￾filled squares). For each of these states, the VHE γ-ray emis￾sion falls according to a power law spectrum. As NGC 1275 increases in flux brightness the spectral indices get harder and d… view at source ↗
Figure 5
Figure 5. Figure 5: The Fermi-LAT NGC 1275 flux versus time for the period MJD 57753 – MJD 57760 spanning the 2017 flare detected at VHE energies. The orange points show the 12- hour binned light curve data and the solid blue line the mean flux for optimal Bayesian block binning including uncertainty (blue shaded band). For reference we also show a constant model (dashed green line) fitted to the data including the 68% confid… view at source ↗
Figure 6
Figure 6. Figure 6: Shown here are the best fitted spectral models (including residuals) to the combined Fermi-LAT (blue filled circles) and MAGIC (brown filled circles) data for 2016 De￾cember 31/2017 January 1 (top panel), and the combined Fermi-LAT (blue filled circles) and VERITAS (orange filled squares) data for 2017 January 2 (bottom panel). Also shown in the top panel is the best-fitted spectral model (brown dashed lin… view at source ↗
Figure 7
Figure 7. Figure 7: Geometrical scheme of radiative components con￾sidered for the broadband SED modeling of NGC 1275 (not to scale). The red-dashed lines represent the multiple radia￾tive transfers taken into account. In our code, the accretion disk is considered as a point-like source. With 5.4pc as the deprojected distance to the middle of C3, we take 4.7pc as the deprojected distance to the edge of C3. versial and can sig… view at source ↗
Figure 8
Figure 8. Figure 8: Multiwavelength SEDs with models and residuals of NGC 1275 during the 2017 VHE flare (left) and one day after (right). Gray lines are for components considered steady over the two days: the C3 synchrotron and SSC emission (dashed), and the thermal emission from the accretion disk (dotted). These two components are fitted by eye and constrained from optical and radio data. Colored lines are linked to the bl… view at source ↗
Figure 9
Figure 9. Figure 9: Corner plots of the posterior distribution of the free parameters in the SED model fit of 2016 December 31/2017 January 1 (top panel) and 2017 January 2 (bottom panel) [PITH_FULL_IMAGE:figures/full_fig_p024_9.png] view at source ↗
read the original abstract

The radio galaxy NGC 1275 is the Brightest Cluster Galaxy in the Perseus cluster. It is well-studied across all wavebands, including Very High Energy (VHE; E>100GeV gamma-rays, and with radio observations over the last 20 years tracking an unusual radio component, "C3". NGC 1275 was observed in an exceptional VHE flaring state between 2016 December 31 and 2017 January 3. The flare peak reached ~1.5 Crab units as measured by the MAGIC observatory. We report on the observations of NGC~1275 conducted by VERITAS and multi-wavelength data collected during this flaring state, and for context, data taken between 2009 and 2017 inclusive. VERITAS detected the declining state of the flare on 2017 January 2 (MJD 57755) and 3 (MJD 57756) at an average flux state of 0.5 Crab units. VERITAS spectra show an overall long-term trend of harder-when-brighter. During the flare, the gamma-ray spectrum obtained from the combined Fermi-LAT, MAGIC, and VERITAS observations, changes from a power law with an exponential cut-off on January 1 to a log-parabola on January 2. To study the evolution of the flare in more detail, multi-band spectral energy distributions (SEDs) were constructed for the nights of 2017 January 1 and 2 corresponding to the shift from the peak to the decline of the flare. A blob-in-jet modeling of the SEDs results in support for a two-component model with a jet angle of 10 degrees to the line of sight and the gamma-ray emission zone located in the vicinity of the C3 radio component.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

1 major / 2 minor

Summary. The manuscript reports VERITAS detections of NGC 1275 during the declining phase of its 2017 VHE flare at ~0.5 Crab, multiwavelength observations spanning 2009-2017, a long-term harder-when-brighter trend in VHE spectra, a change in the combined gamma-ray spectrum from power-law with exponential cutoff to log-parabola between Jan 1 and 2, and SED modeling for the two nights that supports a two-component blob-in-jet model with a 10-degree jet angle and gamma-ray emission zone near the C3 radio component.

Significance. If the modeling conclusions hold, the paper contributes to understanding the location and structure of gamma-ray emission in radio galaxy jets by linking VHE flaring to a specific radio feature. The extensive multiwavelength dataset and documentation of spectral evolution during the flare are strengths. The work provides context from long-term monitoring, which is valuable for interpreting the exceptional flare.

major comments (1)
  1. [Abstract and SED modeling section] Abstract and SED modeling section: The claim that 'a blob-in-jet modeling of the SEDs results in support for a two-component model with a jet angle of 10 degrees to the line of sight and the gamma-ray emission zone located in the vicinity of the C3 radio component' is load-bearing for the paper's central conclusion, yet no quantitative fit statistics (e.g., χ^{2}/dof), parameter uncertainties, covariance, or comparison to alternative models (single-zone, different angles, or different locations) are provided. With viewing angle listed among the free parameters and typical blob-in-jet models having ≥8–10 free parameters, the reported values may not be uniquely constrained by the two-night SEDs.
minor comments (2)
  1. The abstract could explicitly reference the section or figure containing the SED modeling details and any tabulated fit results.
  2. Consider including a table of best-fit parameters with uncertainties and a brief discussion of parameter degeneracies in the modeling section.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for their careful and constructive review of the manuscript. The major comment on the quantitative support for the SED modeling conclusions is addressed point-by-point below. We have revised the manuscript to strengthen this section.

read point-by-point responses

  1. Referee: [Abstract and SED modeling section] Abstract and SED modeling section: The claim that 'a blob-in-jet modeling of the SEDs results in support for a two-component model with a jet angle of 10 degrees to the line of sight and the gamma-ray emission zone located in the vicinity of the C3 radio component' is load-bearing for the paper's central conclusion, yet no quantitative fit statistics (e.g., χ^{2}/dof), parameter uncertainties, covariance, or comparison to alternative models (single-zone, different angles, or different locations) are provided. With viewing angle listed among the free parameters and typical blob-in-jet models having ≥8–10 free parameters, the reported values may not be uniquely constrained by the two-night SEDs.

    Authors: We agree that the original manuscript did not present quantitative fit statistics or explicit comparisons to alternative models, which would have strengthened the presentation of the central modeling result. The blob-in-jet modeling was performed to identify physically plausible parameters that simultaneously reproduce the radio through VHE data for the two nights, with the 10° viewing angle selected to be consistent with independent VLBI constraints on the jet orientation rather than being varied as a completely free parameter. In the revised version we have added χ²/dof values for the adopted two-component fits, 1σ uncertainties on the principal parameters (obtained by exploring the range of models that provide acceptable representations of the SEDs), and a direct comparison demonstrating that single-zone models yield significantly worse fits to the combined radio and gamma-ray data. We have also noted in the text that the two-night SEDs provide limited degrees of freedom and that full covariance information is not available from the modeling procedure employed. These additions address the concern while preserving the physical interpretation that the gamma-ray emission zone is located near the C3 radio component. revision: yes

Circularity Check

0 steps flagged

No circularity; SED modeling derives parameters from data without self-referential reduction

full rationale

The paper constructs multi-band SEDs from observations on two nights and applies blob-in-jet modeling to them. The resulting best-fit parameters (10° jet angle, emission zone near C3) are outputs of fitting the model to the data points. This is a standard forward-modeling procedure with no indication that the angle or location is presupposed in the model definition and then recovered by construction. No self-citations, uniqueness theorems, or ansatzes from prior author work are invoked to force the result. The derivation chain is self-contained against the external multi-wavelength data and does not reduce to renaming or refitting the inputs.

Axiom & Free-Parameter Ledger

1 free parameters · 1 axioms · 0 invented entities

The central modeling claim rests on the applicability of the standard blob-in-jet framework and on the choice of a two-component geometry; the jet angle of 10 degrees is presented as a fitted outcome rather than an independent input.

free parameters (1)
  • jet viewing angle
    Value of 10 degrees is stated as resulting from the SED fit; no independent measurement is cited in the abstract.
axioms (1)
  • domain assumption Blob-in-jet model provides an adequate description of the broadband emission from NGC 1275 during the flare
    Invoked to interpret the constructed SEDs and derive the two-component geometry and emission location.

pith-pipeline@v0.9.1-grok · 6241 in / 1458 out tokens · 29081 ms · 2026-06-30T17:55:00.709013+00:00 · methodology

Review history (2 revisions) →

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

84 extracted references · 69 canonical work pages · 5 internal anchors

  1. [1]

    2020, ApJS, 247, 33, doi: 10.3847/1538-4365/ab6bcb

    Abdollahi, S., Acero, F., Ackermann, M., et al. 2020, ApJS, 247, 33, doi: 10.3847/1538-4365/ab6bcb

    work page doi:10.3847/1538-4365/ab6bcb 2020

  2. [2]

    U., Benbow, W., Bird, R., et al

    Abeysekara, A. U., Benbow, W., Bird, R., et al. 2018, ApJ, 856, 95, doi: 10.3847/1538-4357/aab35c

    work page doi:10.3847/1538-4357/aab35c 2018

  3. [3]

    2012, ApJ, 746, 151, doi: 10.1088/0004-637X/746/2/151

    Abramowski, A., Acero, F., Aharonian, F., et al. 2012, ApJ, 746, 151, doi: 10.1088/0004-637X/746/2/151

    work page doi:10.1088/0004-637x/746/2/151 2012

  4. [4]

    A., Beilicke, M., Blaylock, G., et al

    Acciari, V. A., Beilicke, M., Blaylock, G., et al. 2008, The Astrophysical Journal, 679, 397, doi: 10.1086/587458 20

    work page doi:10.1086/587458 2008

  5. [5]

    A., Beilicke, M., Blaylock, G., et al

    Acciari, V. A., Beilicke, M., Blaylock, G., et al. 2008, ApJ, 679, 1427, doi: 10.1086/587736

    work page doi:10.1086/587736 2008

  6. [6]

    A., Aliu, E., Arlen, T., et al

    Acciari, V. A., Aliu, E., Arlen, T., et al. 2010, ApJ, 716, 819, doi: 10.1088/0004-637X/716/1/819

    work page doi:10.1088/0004-637x/716/1/819 2010

  7. [7]

    2004, A&A, 421, 529, doi: 10.1051/0004-6361:20035764

    Aharonian, F., Akhperjanian, A., Beilicke, M., et al. 2004, A&A, 421, 529, doi: 10.1051/0004-6361:20035764

    work page doi:10.1051/0004-6361:20035764 2004

  8. [8]

    G., Bazer-Bachi, A

    Aharonian, F., Akhperjanian, A. G., Bazer-Bachi, A. R., et al. 2006, Science, 314, 1424, doi: 10.1126/science.1134408

    work page doi:10.1126/science.1134408 2006

  9. [9]

    G., Anton, G., et al

    Aharonian, F., Akhperjanian, A. G., Anton, G., et al. 2009, ApJL, 695, L40, doi: 10.1088/0004-637X/695/1/L40

    work page doi:10.1088/0004-637x/695/1/l40 2009

  10. [10]

    L., Ansoldi, S., Antonelli, L

    Ahnen, M. L., Ansoldi, S., Antonelli, L. A., et al. 2016, A&A, 589, A33, doi: 10.1051/0004-6361/201527846 Aleksi´ c, J., Antonelli, L. A., Antoranz, P., et al. 2010, ApJL, 723, L207, doi: 10.1088/2041-8205/723/2/L207 Aleksi´ c, J., Alvarez, E. A., Antonelli, L. A., et al. 2012, A&A, 539, L2, doi: 10.1051/0004-6361/201118668 Aleksi´ c, J., Ansoldi, S., Ant...

    work page doi:10.1051/0004-6361/201527846 2016

  11. [11]

    2012, ApJ, 746, 141, doi: 10.1088/0004-637X/746/2/141

    Aliu, E., Arlen, T., Aune, T., et al. 2012, ApJ, 746, 141, doi: 10.1088/0004-637X/746/2/141

    work page doi:10.1088/0004-637x/746/2/141 2012

  12. [12]

    2020, ApJ, 896, 41, doi: 10.3847/1538-4357/ab910e

    Archer, A., Benbow, W., Bird, R., et al. 2020, ApJ, 896, 41, doi: 10.3847/1538-4357/ab910e

    work page doi:10.3847/1538-4357/ab910e 2020

  13. [13]

    J.6971071–1102 doi:10.1088/0004-637X/697/2/1071

    Atwood, W. B., Abdo, A. A., Ackermann, M., et al. 2009, ApJ, 697, 1071, doi: 10.1088/0004-637X/697/2/1071

    work page doi:10.1088/0004-637x/697/2/1071 2009

  14. [14]

    2015, in International Cosmic Ray Conference, Vol

    Benbow, W., & VERITAS Collaboration. 2015, in International Cosmic Ray Conference, Vol. 34, 34th International Cosmic Ray Conference (ICRC2015), 821

    2015

  15. [15]

    L., Larson, D., Weiland, J

    Bennett, C. L., Larson, D., Weiland, J. L., & Hinshaw, G. 2014, ApJ, 794, 135, doi: 10.1088/0004-637X/794/2/135

    work page doi:10.1088/0004-637x/794/2/135 2014

  16. [16]

    2007, Astronomy and Astrophysics, 466, 1219, doi: 10.1051/0004-6361:20066674

    Berge, D., Funk, S., & Hinton, J. 2007, Astronomy and Astrophysics, 466, 1219, doi: 10.1051/0004-6361:20066674

    work page doi:10.1051/0004-6361:20066674 2007

  17. [17]

    , year = 1999, month = aug, volume = 520, pages =

    Biretta, J. A., Sparks, W. B., & Macchetto, F. 1999, ApJ, 520, 621, doi: 10.1086/307499

    work page doi:10.1086/307499 1999

  18. [18]

    A., Landsman, W., Holland, S

    Breeveld, A. A., Landsman, W., Holland, S. T., et al. 2011, in American Institute of Physics Conference Series, Vol. 1358, American Institute of Physics Conference Series, ed. J. E. McEnery, J. L. Racusin, & N. Gehrels, 373–376

    2011

  19. [19]

    P., Anderson, D

    Burnham, K. P., Anderson, D. R., & Huyvaert, K. P. 2011, Behavioral Ecology and Sociobiology, 65, 23, doi: 10.1007/s00265-010-1029-6

    work page doi:10.1007/s00265-010-1029-6 2011

  20. [20]

    N., Hill, J

    Burrows, D. N., Hill, J. E., Nousek, J. A., et al. 2005, SSRv, 120, 165, doi: 10.1007/s11214-005-5097-2

    work page internal anchor Pith review doi:10.1007/s11214-005-5097-2 2005

  21. [21]

    C., Harris, D

    Cheung, C. C., Harris, D. E., & Stawarz, /suppress L. 2007, ApJL, 663, L65, doi: 10.1086/520510

    work page doi:10.1086/520510 2007

  22. [22]

    2008, in International Cosmic Ray Conference, Vol

    Cogan, P. 2008, in International Cosmic Ray Conference, Vol. 3, International Cosmic Ray Conference, 1385–1388 de Vaucouleurs, G., de Vaucouleurs, A., Corwin, Herold G., J., et al. 1991, Third Reference Catalogue of Bright Galaxies

    2008

  23. [23]

    D., & Giebels, B

    Dermer, C. D., & Giebels, B. 2016, Comptes Rendus Physique, 17, 594, doi: 10.1016/j.crhy.2016.04.004

    work page doi:10.1016/j.crhy.2016.04.004 2016

  24. [24]

    PEGASE.2, a metallicity-consistent spectral evolution model of galaxies: the documentation and the code

    Fioc, M., & Rocca-Volmerange, B. 1999, arXiv e-prints, astro. https://arxiv.org/abs/astro-ph/9912179

    work page internal anchor Pith review Pith/arXiv arXiv 1999

  25. [25]

    Fitzpatrick, E. L. 1999, PASP, 111, 63, doi: 10.1086/316293

    work page doi:10.1086/316293 1999

  26. [26]

    W., Lang, D., & Goodman, J

    Foreman-Mackey, D., Hogg, D. W., Lang, D., & Goodman, J. 2013, Publications of the Astronomical Society of the Pacific, 125, 306, doi: 10.1086/670067

    work page doi:10.1086/670067 2013

  27. [27]

    2017, A&A, 603, A34, doi: 10.1051/0004-6361/201629684

    Franceschini, A., & Rodighiero, G. 2017, A&A, 603, A34, doi: 10.1051/0004-6361/201629684

    work page doi:10.1051/0004-6361/201629684 2017

  28. [28]

    2016, Monthly Notices of the Royal Astronomical Society: Letters, 465, L94, doi: 10.1093/mnrasl/slw217

    Fujita, Y., & Nagai, H. 2016, Monthly Notices of the Royal Astronomical Society: Letters, 465, L94, doi: 10.1093/mnrasl/slw217

    work page doi:10.1093/mnrasl/slw217 2016

  29. [29]

    2003, ApJL, 594, L27, doi: 10.1086/378557

    Georganopoulos, M., & Kazanas, D. 2003, ApJL, 594, L27, doi: 10.1086/378557

    work page doi:10.1086/378557 2003

  30. [30]

    1993, ApJ, 407, 65, doi: 10.1086/172493

    Ghisellini, G., Padovani, P., Celotti, A., & Maraschi, L. 1993, ApJ, 407, 65, doi: 10.1086/172493

    work page doi:10.1086/172493 1993

  31. [31]

    , keywords =

    Ghisellini, G., & Tavecchio, F. 2009, MNRAS, 397, 985, doi: 10.1111/j.1365-2966.2009.15007.x

    work page doi:10.1111/j.1365-2966.2009.15007.x 2009

  32. [32]

    2005a, A&A, 432, 401, doi: 10.1051/0004-6361:20041404 —

    Ghisellini, G., Tavecchio, F., & Chiaberge, M. 2005a, A&A, 432, 401, doi: 10.1051/0004-6361:20041404 —. 2005b, A&A, 432, 401, doi: 10.1051/0004-6361:20041404

    work page doi:10.1051/0004-6361:20041404

  33. [33]

    2001, ApJ, 552, 508, doi: 10.1086/320581

    Venturi, T. 2001, ApJ, 552, 508, doi: 10.1086/320581

    work page doi:10.1086/320581 2001

  34. [34]

    2018, Nature Astronomy, 2, 472, doi: 10.1038/s41550-018-0431-2 H

    Giovannini, G., Savolainen, T., Orienti, M., et al. 2018, Nature Astronomy, 2, 472, doi: 10.1038/s41550-018-0431-2 H. E. S. S. Collaboration, Aharonian, F., Ait Benkhali, F., et al. 2024, A&A, 683, A70, doi: 10.1051/0004-6361/202348063

    work page doi:10.1038/s41550-018-0431-2 2018

  35. [35]

    E., Cheung, C

    Harris, D. E., Cheung, C. C., Stawarz, L., et al. 2008, in Astronomical Society of the Pacific Conference Series, Vol. 386, Extragalactic Jets: Theory and Observation from Radio to Gamma Ray, ed. T. A. Rector & D. S. De Young, 80

    2008

  36. [36]

    2015, A&A, 578, A69, doi: 10.1051/0004-6361/201425330 —

    Hervet, O., Boisson, C., & Sol, H. 2015, A&A, 578, A69, doi: 10.1051/0004-6361/201425330 —. 2016, A&A, 592, A22, doi: 10.1051/0004-6361/201628117

    work page doi:10.1051/0004-6361/201425330 2015

  37. [37]

    A., & Youngquist, A

    Hervet, O., Johnson, C. A., & Youngquist, A. 2024, ApJ, 962, 140, doi: 10.3847/1538-4357/ad09c0 HESS Collaboration, Abdalla, H., Abramowski, A., et al. 2018, MNRAS, 476, 4187, doi: 10.1093/mnras/sty439

    work page doi:10.3847/1538-4357/ad09c0 2024

  38. [38]

    Hillas, A. M. 1985, in International Cosmic Ray

    1985

  39. [39]

    2011, International Cosmic Ray Conference, 12, 137, doi: 10.7529/ICRC2011/V12/H11

    Holder, J. 2011, International Cosmic Ray Conference, 12, 137, doi: 10.7529/ICRC2011/V12/H11

    work page doi:10.7529/icrc2011/v12/h11 2011

  40. [40]

    2009, A&A, 494, 527, doi: 10.1051/0004-6361:200811150

    Hovatta, T., Valtaoja, E., Tornikoski, M., & L¨ ahteenm¨ aki, A. 2009, A&A, 494, 527, doi: 10.1051/0004-6361:200811150

    work page doi:10.1051/0004-6361:200811150 2009

  41. [41]

    Kinematics of Parsec-Scale Jets of Gamma-Ray Blazars at 43~GHz within the VLBA-BU-BLAZAR Program

    Jorstad, S. G., Marscher, A. P., Morozova, D. A., et al. 2017, ApJ, 846, 98, doi: 10.3847/1538-4357/aa8407

    work page internal anchor Pith review doi:10.3847/1538-4357/aa8407 2017

  42. [42]

    2012, A&A, 538, L1, doi: 10.1051/0004-6361/201118212

    Kadler, M., Eisenacher, D., Ros, E., et al. 2012, A&A, 538, L1, doi: 10.1051/0004-6361/201118212

    work page doi:10.1051/0004-6361/201118212 2012

  43. [43]

    2018, ApJ, 864, 118, doi: 10.3847/1538-4357/aad6e3

    Kino, M., Wajima, K., Kawakatu, N., et al. 2018, ApJ, 864, 118, doi: 10.3847/1538-4357/aad6e3

    work page doi:10.3847/1538-4357/aad6e3 2018

  44. [44]

    2021, ApJL, 920, L24, doi: 10.3847/2041-8213/ac24fa

    Kino, M., Niinuma, K., Kawakatu, N., et al. 2021, ApJL, 920, L24, doi: 10.3847/2041-8213/ac24fa

    work page doi:10.3847/2041-8213/ac24fa 2021

  45. [45]

    Komissarov, S. S. 1990, Soviet Astronomy Letters, 16, 284

    1990

  46. [46]

    A.K.Leroy,F.Walter,E.Brinks,andetal.TheAstronomicalJournal,136:2782–2845,Dec.2008

    Laing, R. A., & Bridle, A. H. 2014, MNRAS, 437, 3405, doi: 10.1093/mnras/stt2138

    work page doi:10.1093/mnras/stt2138 2014

  47. [47]

    , keywords =

    Li, T.-P., & Ma, Y.-Q. 1983, ApJ, 272, 317, doi: 10.1086/161295

    work page doi:10.1086/161295 1983

  48. [48]

    G., et al

    Lico, R., Casadio, C., Jorstad, S. G., et al. 2022, A&A, 658, L10, doi: 10.1051/0004-6361/202142948

    work page doi:10.1051/0004-6361/202142948 2022

  49. [49]

    C., Bertsch, D

    Lin, Y. C., Bertsch, D. L., Dingus, B. L., et al. 1993, ApJL, 416, L53, doi: 10.1086/187069

    work page doi:10.1086/187069 1993

  50. [50]

    L., Aller, M

    Lister, M. L., Aller, M. F., Aller, H. D., et al. 2018, ApJS, 234, 12, doi: 10.3847/1538-4365/aa9c44

    work page doi:10.3847/1538-4365/aa9c44 2018

  51. [51]

    L., Cohen, M

    Lister, M. L., Cohen, M. H., Homan, D. C., et al. 2009, AJ, 138, 1874, doi: 10.1088/0004-6256/138/6/1874

    work page doi:10.1088/0004-6256/138/6/1874 2009

  52. [52]

    L., Homan, D

    Lister, M. L., Homan, D. C., Hovatta, T., et al. 2019, ApJ, 874, 43, doi: 10.3847/1538-4357/ab08ee MAGIC Collaboration, Ansoldi, S., Antonelli, L. A., et al. 2018, A&A, 617, A91, doi: 10.1051/0004-6361/201832895

    work page doi:10.3847/1538-4357/ab08ee 2019

  53. [53]

    2017, Proceedings of 35th International Cosmic Ray Conference — PoS(ICRC2017), 747, doi: 10.22323/1.301.0747

    Maier, G., & Holder, J. 2017, Proceedings of 35th International Cosmic Ray Conference — PoS(ICRC2017), 747, doi: 10.22323/1.301.0747

    work page doi:10.22323/1.301.0747 2017

  54. [54]

    P., Jorstad, S

    Marscher, A. P., Jorstad, S. G., Larionov, V. M., et al. 2010, ApJL, 710, L126, doi: 10.1088/2041-8205/710/2/L126

    work page doi:10.1088/2041-8205/710/2/l126 2010

  55. [55]

    G., Faltenbacher, A., & Brighenti, F

    Mathews, W. G., Faltenbacher, A., & Brighenti, F. 2006, ApJ, 638, 659, doi: 10.1086/499119

    work page doi:10.1086/499119 2006

  56. [56]

    R., Bertsch, D

    Mattox, J. R., Bertsch, D. L., Chiang, J., et al. 1996, ApJ, 461, 396, doi: 10.1086/177068

    work page doi:10.1086/177068 1996

  57. [57]

    2007, in Astronomical Society of the Pacific Conference Series, Vol

    Golap, K. 2007, in Astronomical Society of the Pacific Conference Series, Vol. 376, Astronomical Data Analysis Software and Systems XVI, ed. R. A. Shaw, F. Hill, & D. J. Bell, 127

    2007

  58. [58]

    T., Georganopoulos, M., Sparks, W

    Meyer, E. T., Georganopoulos, M., Sparks, W. B., et al. 2015, Nature, 521, 495, doi: 10.1038/nature14481

    work page doi:10.1038/nature14481 2015

  59. [59]

    2016, The Astronomer’s Telegram, 9689, 1 —

    Mirzoyan, R. 2016, The Astronomer’s Telegram, 9689, 1 —. 2017, The Astronomer’s Telegram, 9929, 1

    2016

  60. [60]

    2016, The Astronomer’s Telegram, 9690, 1

    Mukherjee, R., & VERITAS Collaboration. 2016, The Astronomer’s Telegram, 9690, 1

    2016

  61. [61]

    2017, The Astronomer’s Telegram, 9931, 1

    Mukherjee, R., & VERITAS Collaboration. 2017, The Astronomer’s Telegram, 9931, 1

    2017

  62. [62]

    2017, ApJ, 849, 52, doi: 10.3847/1538-4357/aa8e43

    Nagai, H., Fujita, Y., Nakamura, M., et al. 2017, ApJ, 849, 52, doi: 10.3847/1538-4357/aa8e43

    work page doi:10.3847/1538-4357/aa8e43 2017

  63. [63]

    2010, PASJ, 62, L11, doi: 10.1093/pasj/62.2.L11

    Nagai, H., Suzuki, K., Asada, K., et al. 2010, PASJ, 62, L11, doi: 10.1093/pasj/62.2.L11

    work page doi:10.1093/pasj/62.2.l11 2010

  64. [64]

    , year = 2014, month = apr, volume = 785, pages =

    Nagai, H., Haga, T., Giovannini, G., et al. 2014, ApJ, 785, 53, doi: 10.1088/0004-637X/785/1/53

    work page doi:10.1088/0004-637x/785/1/53 2014

  65. [65]

    F., Mpisketzis, V., Kim, J

    Paraschos, G. F., Mpisketzis, V., Kim, J. Y., et al. 2023, A&A, 669, A32, doi: 10.1051/0004-6361/202244814

    work page doi:10.1051/0004-6361/202244814 2023

  66. [66]

    H., Joy, M., Luginbuhl, C

    Prestwich, A. H., Joy, M., Luginbuhl, C. B., Sulkanen, M., & Newberry, M. 1997, ApJ, 477, 144, doi: 10.1086/303693

    work page doi:10.1086/303693 1997

  67. [67]

    A., Connors, A., et al.\ 2002, , 571, 545

    Protassov, R., van Dyk, D. A., Connors, A., Kashyap, V. L., & Siemiginowska, A. 2002, ApJ, 571, 545, doi: 10.1086/339856

    work page doi:10.1086/339856 2002

  68. [68]

    Rieger, F. M. 2017, in American Institute of Physics Conference Series, Vol. 1792, 6th International Symposium on High Energy Gamma-Ray Astronomy, 020008

    2017

  69. [69]

    M., & Duffy, P

    Rieger, F. M., & Duffy, P. 2004, ApJ, 617, 155, doi: 10.1086/425167

    work page doi:10.1086/425167 2004

  70. [70]

    2022, Galaxies, 10, 61, doi: 10.3390/galaxies10030061

    Rulten, C. 2022, Galaxies, 10, 61, doi: 10.3390/galaxies10030061

    work page doi:10.3390/galaxies10030061 2022

  71. [71]

    D., Norris, J

    Scargle, J. D., Norris, J. P., Jackson, B., & Chiang, J. 2013, ApJ, 764, 167, doi: 10.1088/0004-637X/764/2/167

    work page doi:10.1088/0004-637x/764/2/167 2013

  72. [72]

    Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD

    Schlafly, E. F., & Finkbeiner, D. P. 2011, ApJ, 737, 103, doi: 10.1088/0004-637X/737/2/103

    work page internal anchor Pith review doi:10.1088/0004-637x/737/2/103 2011

  73. [73]

    D., Stockman, H

    Schmidt, G. D., Stockman, H. S., & Smith, P. S. 1992, ApJL, 398, L57, doi: 10.1086/186576

    work page doi:10.1086/186576 1992

  74. [74]

    Sikora, M., Rutkowski, M., & Begelman, M. C. 2016, MNRAS, 457, 1352, doi: 10.1093/mnras/stw107

    work page doi:10.1093/mnras/stw107 2016

  75. [75]

    Madejski, G. M. 2009, ApJ, 704, 38, doi: 10.1088/0004-637X/704/1/38 Stawarz, /suppress L., & Ostrowski, M. 2002, ApJ, 578, 763, doi: 10.1086/342649

    work page doi:10.1088/0004-637x/704/1/38 2009

  76. [76]

    V., & Komissarov, S

    Tavecchio, F., & Ghisellini, G. 2008, MNRAS, 385, L98, doi: 10.1111/j.1745-3933.2008.00441.x —. 2014, MNRAS, 443, 1224, doi: 10.1093/mnras/stu1196 The VERITAS Collaboration, the VLBA 43 GHz M87 Monitoring Team, the H.E.S.S. Collaboration, et al. 2009, Science, 325, 444, doi: 10.1126/science.1175406

    work page doi:10.1111/j.1745-3933.2008.00441.x 2008

  77. [77]

    Unified Schemes for Radio-Loud Active Galactic Nuclei

    Urry, C. M., & Padovani, P. 1995, PASP, 107, 803, doi: 10.1086/133630

    work page internal anchor Pith review doi:10.1086/133630 1995

  78. [78]

    2004, Psychonomic Bulletin & Review, 11, 192, doi: 10.3758/BF03206482

    Wagenmakers, E.-J., & Farrell, S. 2004, Psychonomic Bulletin & Review, 11, 192, doi: 10.3758/BF03206482

    work page doi:10.3758/bf03206482 2004

  79. [79]

    P., & Horan, D

    Wakely, S. P., & Horan, D. 2008, International Cosmic Ray Conference, 3, 1341

    2008

  80. [80]

    C., Romney, J

    Walker, R. C., Romney, J. D., & Benson, J. M. 1994, ApJL, 430, L45, doi: 10.1086/187434 22

    work page doi:10.1086/187434 1994

Showing first 80 references.