First Hard X-ray Observation of a Compact Symmetric Object: A Broadband X-ray Study of a radio galaxy OQ+208 with NuSTAR and Chandra

Aneta Siemiginowska; Giulia Migliori; Luisa Ostorero; Lukasz Stawarz; Malgosia Sobolewska; Martin Hardcastle; Matteo Guainazzi

First Hard X-ray Observation of a Compact Symmetric Object: A Broadband X-ray Study of a radio galaxy OQ+208 with NuSTAR and Chandra

T0 review · 0 major / 6 minor · reviewed 2026-08-14 · deepseek-v4-flash

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Pith's one-line read A Compact Symmetric Object is detected in hard X-rays for the first time, establishing young radio sources as a new class of NuSTAR emitters.

desk verdict First hard X-ray detection of a CSO is real and well supported; the interpretive overreach is modest and fixable. read the letter →

arxiv 1909.02084 v1 pith:Z6MSR745 submitted 2019-09-04 astro-ph.HE

Malgosia Sobolewska , Aneta Siemiginowska , Matteo Guainazzi , Martin Hardcastle , Giulia Migliori , Luisa Ostorero , Lukasz Stawarz This is my paper · ORCID

classification astro-ph.HE

keywords compactsymmetricobjectOQ+208hardX-rayNuSTARAGNtorusspectroscopyyoungradiogalaxiesCompton-thick

verification ladder T0 review T1 audit T2 compute T3 formal

The pith

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

The reading

The paper reports the first hard X-ray detection of a Compact Symmetric Object, a radio galaxy whose twin jets are only about 250 years old and still confined to the central 10 parsecs of the host. The NuSTAR observation catches OQ+208 at up to 30 keV, with the 10–30 keV detection at the 6σ level, and Chandra and archival XMM-Newton spectra extend the coverage down to 0.5 keV. Joint modeling shows that the intrinsic emission is a hard power law with photon index Γ ≈ 1.45, absorbed by cold material with column density $10^{23}$–$10^{24}$ $cm^{-2}$, which the authors interpret as a dusty torus around the black hole. The fit prefers a porous torus in which the line-of-sight column is a few times lower than the average column, with an optically broad-line but X-ray-obscured source as the alternative. The detection opens the >10 keV band to the study of radio sources in the first centuries of their expansion.

What carries the argument

The spectral model is the load-bearing machinery: the observed spectrum is written as $A_{\rm instr}\, M_{\rm abs,1}\,[C_{\rm scat}\,{\rm cutoffpl} + M_{\rm abs,2}\,{\rm cutoffpl} + {\rm torus}]$, where $M_{\rm abs,1}$ is Galactic plus host-galaxy absorption, $M_{\rm abs,2}$ is the angle-dependent line-of-sight absorption table of Yaqoob (2012), and 'torus' is the self-consistent reflection plus fluorescent Fe Kα, Kβ model of Baloković et al. (2018). The key model comparison is between a linked scenario, in which the line-of-sight column equals the average torus column, and an unlinked (porous) scenario in which they are free to differ; the comparable fit quality of the porous case, together with the large scattered fraction, supports the paper's conclusion that the torus may be porous. The inclination is fixed near 85°, assuming the radio jet lies in the plane of the sky.

What would settle it

A higher-signal NuSTAR spectrum of OQ+208 that measures the Fe Kα line and the reflection continuum independently of the assumed torus geometry could decide the porous-torus claim: if the line-of-sight column and average torus column converge to the same value, the porous interpretation fails. Alternatively, a detection of extended X-ray emission, or an SED showing radio-lobe inverse-Compton emission at the predicted level, would falsify the conclusion that the hard X-rays do not come from the lobes.

Watch

Extended reading notes

Core claim

The central discovery is that OQ+208, a Compact Symmetric Object at redshift 0.0766 with a radio source aged 255 ± 17 yr and a double-lobed structure ~10 pc across, emits X-rays up to 30 keV; the NuSTAR detection in the 10–30 keV band is significant at the 6σ level, and no other CSO had been seen above 10 keV. By fitting the new Chandra and NuSTAR spectra together with archival XMM-Newton data, the authors find that the primary continuum is a hard power law with photon index Γ = 1.45 (range 1.44–1.45 in the two fitted scenarios), absorbed by an equivalent hydrogen column density of $10^{23}$–$10^{24}$ $cm^{-2}$, and accompanied by a strong neutral Fe Kα line and a scattered soft component dominating below 4 keV. The preferred geometry is a torus with a covering factor above 0.6; when the line-of-sight and average torus column densities are allowed to differ, the average column rises to ~1.3×$10^{24}$ $cm^{-2}$, classifying the source as Compton-thick with a porous obscurer. The measured 0.5–30 keV intrinsic luminosity is ~$10^{43}$ erg $s^{-1}$, lower than the inverse-Compton emission predicted for radio lobes in equipartition, so the authors attribute the hard X-rays to an accretion disk corona or jets rather than to the young lobes themselves.

Load-bearing premise

The spectral decomposition assumes the Baloković et al. (2018) torus model correctly describes the obscuring matter and that the torus is seen at an inclination near 85 degrees; if the absorber is clumpy in a different way or the inclination is wrong, the fitted column densities and the porous-torus conclusion would not hold.

Editorial extensions

If this is right

CSOs are established as a new class of hard X-ray sources accessible to NuSTAR, so future surveys can measure their 10–30 keV properties directly.
The coexistence of a ~250 yr old radio source with a dense, high-covering-factor torus implies that obscuring material and black-hole accretion are in place during the earliest phase of jet expansion.
The measured photon index Γ≈1.45 is too hard for typical Seyfert-like AGN coronae at these luminosities but resembles the hard state of black hole binaries, suggesting a jet or coronal origin.
The observed X-ray luminosity is an order of magnitude below both the lobe inverse-Compton prediction and the bolometric-correction expectation for a radio-loud AGN of this bolometric luminosity, so the X-ray production mechanism in OQ+208 is unusually inefficient.
The apparent ~50% flux increase between 2014 and 2016, if real, can be explained by a change in the porosity of the absorber rather than by intrinsic continuum variability.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

Because NuSTAR can see through columns up to ~10^24 cm^-2, the same joint Chandra/NuSTAR strategy should detect other CSOs and measure whether dense tori are a universal feature of newborn radio sources; if most CSOs are Compton-thick, current X-ray luminosity functions of young AGN are systematically biased low.
The porous-torus interpretation implies that optical classification of young radio galaxies as broad-line (type 1) does not rule out heavy X-ray absorption; a practical test is to compare [O III] or mid-infrared-based column estimates with X-ray NH in a sample of CSOs.
If the hard X-ray emission indeed tracks the corona or jet rather than the lobes, variability monitoring at 10–30 keV could directly probe accretion-state changes in a source whose jet is only centuries old, effectively a 'baby AGN' analogue of hard-state X-ray binaries.

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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Desk Editor's Note

read the letter

First: the hard X-ray detection is real. OQ+208 shows a 6-sigma excess in NuSTAR's 10-30 keV band, with ~1000 net counts. That makes it the first CSO seen above 10 keV, and it turns CSOs into a NuSTAR source class. The companion Chandra and archival XMM data are folded in properly, and the spectral decomposition, while model-dependent, is statistically acceptable. The paper is worth a serious referee.

What is new beyond the detection: the joint 0.5-30 keV spectral fit gives the first broadband view of a CSO's X-ray continuum. The results--photon index around 1.45, absorbing column in the 10^23-10^24 range, strong Fe line, large covering factor--are the kind of constraints people need to compare young radio sources with theoretical lobe models. The authors also use the Chandra data to argue against diffuse emission and are appropriately cautious about the 30" companion source.

Soft spots are mostly in the interpretation layer. The derived column densities and the "porous torus" conclusion rest on the Baloković 2018 torus model with inclination fixed at about 85 degrees, justified by assuming the radio jet lies in the plane of the sky. That assumption is defensible but not certain; if the inclination is closer to 45 degrees (as some radio work hints), the NH values and the torus porosity story would shift. The detection itself doesn't depend on those choices. The cross-normalization between Chandra and NuSTAR implies possible ~50% variability, which is discussed honestly. And a weakness in the current text is that Section 3.2 appears to swap the linked and unlinked NH,2 values relative to Table 2; it reads like a transcription error and should be fixed, but it does not affect the broad conclusions.

The bolometric comparison uses two in-preparation references; not ideal, but the authors flag it and the central claim doesn't ride on it. The citation pattern is reasonable, with self-citations to S16 and related work appropriate since they built directly on that sample.

Bottom line: this is a solid, genuinely new observational result with sensible analysis and appropriately hedged interpretation. It deserves peer review and should be accepted after minor revisions. I'd cite it if I worked on young radio sources, and I'd bring it to a reading group focused on AGN, though it won't change anyone's worldview.

Referee Report

0 major / 6 minor

Summary. This paper reports the first hard X-ray (>10 keV) detection of a Compact Symmetric Object (CSO). The authors analyze new NuSTAR and Chandra observations of the radio galaxy OQ+208 together with archival XMM-Newton data. The source is detected by NuSTAR up to 30 keV, with a claimed 6σ significance in the 10–30 keV band. Joint spectral fitting using a torus-reflection model yields a photon index Γ ≈ 1.45, an intrinsic 0.5–30 keV luminosity of ~10^43 erg/s, and equivalent hydrogen column densities of ~10^23–10^24 cm^-2, with a large covering factor. The authors consider two scenarios in which the line-of-sight and average torus column densities are linked or unlinked, the latter suggesting a porous torus, and they also discuss an alternative type-12 AGN interpretation. The observed X-ray flux is lower than predicted by expanding-lobe inverse-Compton models, favoring an accretion-disk-corona or jet origin.

Significance. The paper's central claim — that NuSTAR has detected OQ+208 up to 30 keV, making CSOs a new class of hard X-ray emitters — appears robust. The detection is supported by substantial background-subtracted NuSTAR counts (Table 1), and the joint multi-instrument spectral analysis is carefully performed with a physically motivated torus model. The reported parameters, with asymmetric uncertainties and cross-normalization checks, are plausible. The main interpretive caveats (fixed 85° inclination, reliance on the Baloković et al. 2018 torus geometry, and comparison with external lobe-emission predictions from Ostorero et al. 2010) are acknowledged by the authors and do not affect the detection itself. This paper provides a valuable first step toward characterizing the high-energy properties of young radio sources.

minor comments (6)

[§3.2, Table 2] The numerical values for NH,2 and N_torus in Section 3.2 appear to be interchanged between the linked and unlinked scenarios relative to Table 2. In the linked column of Table 2, NH,2 = N_torus = (4.4+0.1−0.2)×10^23 cm^-2, while the unlinked column gives NH,2 = (3.2+0.9−0.4)×10^23 cm^-2 and N_torus = (1.3+0.9−0.3)×10^24 cm^-2; the text states the opposite. Please correct the text so that it matches the table and that the following discussion of a statistically significant difference between the two column densities refers to the unlinked scenario.
[§3.1] The 6σ detection significance in the 10–30 keV band is stated without describing the calculation. Given that this is the central new result, please add a brief explanation (e.g., net source counts, background, and the statistic used) or cite a standard tool, so that the significance can be independently assessed.
[§2.3] The inclination is fixed at about 85° based on the assumption that the radio jet is in the plane of the sky, whereas Stanghellini et al. (1997) discuss a possible jet inclination of about 45°. The authors should state whether the derived column densities and torus parameters are sensitive to this choice within the Baloković et al. (2018) model, or explicitly acknowledge this as a limitation in the interpretation.
[§4.1] The conclusion that the observed X-ray emission is weaker than the expanding-lobe inverse-Compton prediction relies on the Ostorero et al. (2010) model. The authors should clarify that this comparison assumes near-equipartition between magnetic and electron energy densities, since the alternative (magnetic-pressure-dominated lobes) is mentioned but not quantified.
[§4.2] The term 'type-12 AGN' is used; I presume this is a typographical rendering of 'Type 1.2' or an intermediate type. Please correct the nomenclature.
[§2.3, Table 2] The model description in the text uses A_instr for cross-normalization, but Table 2 labels these as A_chandra, A_xmm, A_nA, and A_nB. Please unify the notation.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the NuSTAR hard-X-ray detection is a count-based result and the spectral interpretation rests on external models, not on fitted predictions.

full rationale

The paper's central claim, the first hard X-ray detection of a CSO, is a detection claim derived from NuSTAR source and background counts in the 10-30 keV band, reported as a 6-sigma significance in Section 3.1. This does not depend on the spectral model or on any fitted parameter, so it cannot reduce by construction to an input. The spectral decomposition uses the torus model of Balokovic et al. (2018), an external public model, and the fixed inclination angle is an explicitly stated assumption based on the radio jet geometry, not a hidden input smuggled through self-citation. The porous-torus conclusion is presented as a fit outcome of the unlinked NH,2 and Ntorus_H scenario, with C-statistic comparison, rather than as a prediction; a fitted parameter is not being renamed as a prediction. The comparison with the expanding-lobe model uses the external predictions of Ostorero et al. (2010), which were not fitted to these data, so the observed shortfall is an independent falsifiable test. Self-citations to Siemiginowska et al. (2016), Sobolewska et al. (2019), and Migliori et al. (2016) appear in contextual statements about prior X-ray and gamma-ray work and do not carry the derivation. No equation or model component in the paper is equivalent to the target result by definition. Therefore the analysis is self-contained for its detection claim, and the interpretive caveats are correctness risks, not circularity.

Assumptions & free parameters 8 free parameters · 4 assumptions · 0 invented entities

The central results rest on standard X-ray spectral fitting with existing torus models. No new physical entities are introduced; the 'porous torus' scenario is a geometric configuration of known material. All derived quantities (photon index, column densities, covering factor, line and scattering normalizations) are free parameters fitted to the data.

free parameters (8)

Photon index (Gamma) = 1.45 (+0.11/-0.01)
Slope of the primary X-ray power law; fitted to the joint Chandra/NuSTAR/XMM-Newton spectrum.
Line-of-sight intrinsic column (NH,2) = 0.32 to 0.44e24 cm^-2
Column density along the line of sight; fitted in both linked and unlinked scenarios.
Torus column (N_torus) = 1.3e24 or 3.2e23 cm^-2
Average column density of the torus; fitted when unlinked from NH,2.
Covering factor (CF) = 0.91 (+0.09/-0.32 or -0.44)
Fraction of the sky covered by the torus; fitted.
Line normalization (C_line) = 3.5 or 8.9
Normalization of the fluorescent Fe K-alpha line component; fitted to account for excess line emission.
Scattering fraction (C_scat) = 0.61 to 0.69
Fraction of the primary power law scattered into the line of sight; fitted to the soft X-ray excess.
Host galaxy column (NH,1) = 6.6 to 6.8e20 cm^-2
Column density attributed to the host galaxy; fitted.
Cross-normalization constants (A_chandra, A_xmm, A_FPMA, A_FPMB) = 1.0, 1.05 to 1.09, 1.36 to 1.38, 1.28 to 1.30
Relative normalizations between the four instruments; fitted, with NuSTAR higher by 30 to 40 percent than Chandra.

assumptions (4)

domain assumption The Balokovic et al. (2018) torus model accurately describes the geometry and emission of the obscuring matter around the black hole.
The model is used to compute absorption, reflection, and fluorescent lines; any mismatch affects the fitted parameters. Quoted in Section 2.3.
domain assumption The radio jet is oriented in the plane of the sky, giving an inclination of about 85 degrees for the torus.
Assumed in Section 2.3 to fix the inclination parameter in the Balokovic model; a different inclination would change the derived column densities.
domain assumption The primary X-ray power law has an exponential cutoff at 300 keV.
Fixed at Ecut = 300 keV in the model (Table 2); the true cutoff is unknown and could affect the intrinsic luminosity.
domain assumption The iron abundance in the torus is Solar.
Fixed at A_Fe = 1; the alternative, varying the abundance, yields fits of comparable quality with abundance about 3 to 9 times Solar.

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Cite this review

Pith. "Pith review of First Hard X-ray Observation of a Compact Symmetric Object: A Broadband X-ray Study of a radio galaxy OQ+208 with NuSTAR and Chandra." pith.science (2026). https://pith.science/paper/Z6MSR745

@misc{pith2026190902084,
  author       = {Pith},
  title        = {Pith review of: First Hard X-ray Observation of a Compact Symmetric Object: A Broadband X-ray Study of a radio galaxy OQ+208 with NuSTAR and Chandra},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/Z6MSR745}},
  note         = {Machine review of arXiv:1909.02084}
}

abstract

Compact Symmetric Objects (CSOs) have been observed with Chandra and XMM-Newton to gain insights into the initial stages of a radio source evolution and probe the black hole activity at the time of relativistic outflow formation. However, there have been no CSO observations to date at the hard X-ray energies (> 10 keV), impeding our ability to robustly constrain the properties of the intrinsic X-ray emission and of the medium surrounding the young expanding jets. We present the first hard X-ray observation of a CSO performed with NuSTAR. Our target, OQ+208, is detected up to 30 keV, and thus we establish CSOs as a new class of NuSTAR sources. We analyze the NuSTAR data jointly with our new Chandra and archival XMM-Newton data and find that a young, ~250 years old, radio jet spanning the length of ~10 pc coexists with cold obscuring matter, consistent with a dusty torus, with an equivalent hydrogen column density $N_H = 10^{23}$-$10^{24}$ cm$^{-2}$. The primary X-ray emission is characterized by a photon index $\Gamma \sim 1.45$ and intrinsic 0.5-30 keV luminosity $L \sim 10^{43}$ erg s$^{-1}$. The results of our spectral modeling and broad-line optical classification of the source suggest a porous structure of the obscuring torus. Alternatively, the source may belong to the class of optically un-obscured/X-ray obscured AGN. The observed X-ray emission is too weak compared to that predicted by the expanding radio lobes model, leaving an accretion disk corona or jets as the possible origins of the X-ray emission from this young radio galaxy.

Figures

Figures reproduced from arXiv: 1909.02084 by the authors.

**Figure 1.** — Left: Chandra ACIS-S image of OQ +208 in the 0.5-7 keV energy range, with the source region marked with the green circle with the radius of 1.500 (corresponding to 2.1 kpc at the redshift of the source). The pixel size is 0.24900 . Center: The Chandra ACIS-S image binned to pixel size of 0.49200 showing a larger view of the area with the XMM-Newton extraction region marked with the green circle with the radius of … view at source ↗

**Figure 2.** — Top: Surface brightness profile of OQ +208 resulting from the Chandra image. The solid line shows the model of Chandra point spread function corresponding to a point source. Bottom: Model residuals of the fit. No evidence for an extended X-ray emission is detected. the Chandra image nor the broad-band X-ray spectrum provided evidence for the presence of an extended X-ray emission ( [PITH_FULL_IMAGE:figures/full_… view at source ↗

**Figure 3.** — Top: Unfolded data and models from the simultaneous fit of the new Chandra and NuSTAR, and archival XMM-Newton PN data sets in the scenario with the line-of-sight and torus hydrogen column densities linked to each other. The unlinked scenario results in a fit of comparable quality. Center: Corresponding data to model ratios. The vertical dotted line indicates the rest-frame energy of the 6.4 keV Fe fluorescent em… view at source ↗

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Forward citations

Cited by 1 Pith paper

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

The long-term optical flux variations of Compact Symmetric Objects
astro-ph.GA 2025-05 conditional novelty 6.0 of 10

Compact symmetric objects show low-amplitude optical variability and a bluer-when-brighter trend, with weaker amplitude than blazars, consistent with a jet-origin interpretation.

Reference graph

Works this paper leans on

34 extracted references · 29 canonical work pages · cited by 1 Pith paper

[1]

Jacoby G

Arnaud, K.A., 1996, Astronomical Data Analysis Software and Systems V, eds. Jacoby G. and Barnes J., p17, ASP Conf. Series volume 101 Balokovi´ c, M., Brightman, M., Harrison, F. A., et al. 2018, ApJ, 854, 42 Broadband X-ray Study of OQ +208 7

work page 1996
[2]

C., & Cioﬃ, D

Begelman, M. C., & Cioﬃ, D. F. 1989, ApJ, 345, L21

work page 1989
[3]

2011, A&A, 530, A42 Del Moro, A., Alexander, D

Corral, A., Della Ceca, R., Caccianiga, A., et al. 2011, A&A, 530, A42 Del Moro, A., Alexander, D. M., Aird, J. A., et al. 2017, ApJ, 849, 57

work page 2011
[4]

2007, A&A Rev., 15, 1

Done, C., Gierli´ nski, M., & Kubota, A. 2007, A&A Rev., 15, 1

work page 2007
[5]

2018, ApJ, 869, L36

Fabbiano, G., Paggi, A., Siemiginowska, A., et al. 2018, ApJ, 869, L36

work page 2018
[6]

2019, ApJ, 870, 69

Fabbiano, G., Siemiginowska, A., Paggi, A., et al. 2019, ApJ, 870, 69

work page 2019
[7]

2006, Proc

Fruscione, A., et al. 2006, Proc. SPIE, 6270, 60

work page 2006
[8]

2004, A&A, 421, 461

Stanghellini, C. 2004, A&A, 421, 461

work page 2004

Show all 34 references

[9]

A., Craig, W

Harrison, F. A., Craig, W. W., Christensen, F. E., et al. 2013, ApJ, 770, 103

2013
[10]

S., & Begelman, M

Heinz, S., Reynolds, C. S., & Begelman, M. C. 1998, ApJ, 501, 126

1998
[11]

2013, ApJS, 208, 19

Hinshaw, G., Larson, D., Komatsu, E., et al. 2013, ApJS, 208, 19

2013
[12]

2019, ApJ, submitted

Kosmaczewski, E., Stawarz, L., W´ ojtowicz, A., et al. 2019, ApJ, submitted

2019
[13]

M., Alatalo, K., & Appleton, P

Lanz, L., Ogle, P. M., Alatalo, K., & Appleton, P. N. 2016, ApJ, 826, 29

2016
[14]

K., Beardmore, A

Madsen, K. K., Beardmore, A. P., Forster, K., et al. 2017, AJ, 153, 2

2017
[15]

2016, ApJ, 830, 100

Marchesi, S., Lanzuisi, G., Civano, F., et al. 2016, ApJ, 830, 100

2016
[16]

2017, MNRAS, 470, 4039

Marinucci, A., Bianchi, S., Fabbiano, G., et al. 2017, MNRAS, 470, 4039

2017
[17]

2014, MNRAS, 437, 3550

Merloni, A., Bongiorno, A., Brusa, M., et al. 2014, MNRAS, 437, 3550

2014
[18]

C., et al

Migliori, G., Siemiginowska, A., Kelly, B. C., et al. 2014, ApJ, 780, 165

2014
[19]

2016, ApJ, 821, L31

Migliori, G., Siemiginowska, A., Sobolewska, M., et al. 2016, ApJ, 821, L31

2016
[20]

2009, ApJ, 695, 793

Netzer, H. 2009, ApJ, 695, 793

2009
[21]

2010, ApJ, 715, 1071

Ostorero, L., Moderski, R., Stawarz, L., et al. 2010, ApJ, 715, 1071

2010
[22]

A., & McClintock, J

Remillard, R. A., & McClintock, J. E. 2006, ARA&A, 44, 49

2006
[23]

S., Heinz, S., & Begelman, M

Reynolds, C. S., Heinz, S., & Begelman, M. C. 2001, ApJ, 549, L179

2001
[24]

C., Brotherton, M

Runnoe, J. C., Brotherton, M. S., & Shang, Z. 2012, MNRAS, 426, 2677

2012
[25]

2009, Astronomische Nachrichten, 330, 264

Siemiginowska, A. 2009, Astronomische Nachrichten, 330, 264

2009
[26]

2016, ApJ, 823, 57 (S16)

Siemiginowska, A., Sobolewska, M., Migliori, G., et al. 2016, ApJ, 823, 57 (S16)

2016
[27]

2019, ApJ, 871, 71

Sobolewska, M., Siemiginowska, A., Guainazzi, M., et al. 2019, ApJ, 871, 71

2019
[28]

P., Baum, S

Stanghellini, C., O’Dea, C. P., Baum, S. A., & Laurikainen, E. 1993, ApJS, 88, 1

1993
[29]

P., Baum, S

Stanghellini, C., ODea, C. P., Baum, S. A., Dallacasa, D., Fanti, R., & Fanti, C. 1997, A&A, 325, 943

1997
[30]

1997, A&A, 318, 376

Stanghellini, C., Bondi, M., Dallacasa, D., et al. 1997, A&A, 318, 376

1997
[31]

C., et al

Stawarz, L., Ostorero, L., Begelman, M. C., et al. 2008, ApJ, 680, 911

2008
[32]

2009, A&A, 501, 89

Tengstrand, O., Guainazzi, M., Siemiginowska, A., et al. 2009, A&A, 501, 89

2009
[33]

Y., Bicknell, G

Wagner, A. Y., Bicknell, G. V., & Umemura, M. 2012, ApJ, 757, 136

2012
[34]

A., et al

Wu, F., An, T., Baan, W. A., et al. 2013, A&A, 550, A113

2013

Pith tools

Reviewed August 14, 2026 · model on record in the stance chip above.

[1] [1]

Jacoby G

Arnaud, K.A., 1996, Astronomical Data Analysis Software and Systems V, eds. Jacoby G. and Barnes J., p17, ASP Conf. Series volume 101 Balokovi´ c, M., Brightman, M., Harrison, F. A., et al. 2018, ApJ, 854, 42 Broadband X-ray Study of OQ +208 7

work page 1996

[2] [2]

C., & Cioﬃ, D

Begelman, M. C., & Cioﬃ, D. F. 1989, ApJ, 345, L21

work page 1989

[3] [3]

2011, A&A, 530, A42 Del Moro, A., Alexander, D

Corral, A., Della Ceca, R., Caccianiga, A., et al. 2011, A&A, 530, A42 Del Moro, A., Alexander, D. M., Aird, J. A., et al. 2017, ApJ, 849, 57

work page 2011

[4] [4]

2007, A&A Rev., 15, 1

Done, C., Gierli´ nski, M., & Kubota, A. 2007, A&A Rev., 15, 1

work page 2007

[5] [5]

2018, ApJ, 869, L36

Fabbiano, G., Paggi, A., Siemiginowska, A., et al. 2018, ApJ, 869, L36

work page 2018

[6] [6]

2019, ApJ, 870, 69

Fabbiano, G., Siemiginowska, A., Paggi, A., et al. 2019, ApJ, 870, 69

work page 2019

[7] [7]

2006, Proc

Fruscione, A., et al. 2006, Proc. SPIE, 6270, 60

work page 2006

[8] [8]

2004, A&A, 421, 461

Stanghellini, C. 2004, A&A, 421, 461

work page 2004