Probing restarting activity in hard X-ray selected giant radio galaxies

G. Bruni; F. Ursini; F. Panessa; L. Bassani; A. Bazzano; A. J. Bird; E. Chiaraluce; D. Dallacasa; M. Fiocchi; M. Giroletti; L. Hernández-García; A. Malizia; M. Molina; L. Saripalli; P. Ubertini; T. Venturi

doi:10.1017/s1743921319003478

Probing restarting activity in hard X-ray selected giant radio galaxies

Proceedings of the International Astronomical Union ◽

10.1017/s1743921319003478 ◽

2018 ◽

Vol 14 (A30) ◽

pp. 66-69

Author(s):

G. Bruni ◽

F. Ursini ◽

F. Panessa ◽

L. Bassani ◽

A. Bazzano ◽

...

Keyword(s):

Radio Galaxies ◽

High Luminosity ◽

X Ray ◽

The Universe ◽

Multiple Episodes ◽

Individual Objects

AbstractWith their sizes larger than 0.7 Mpc, Giant Radio Galaxies (GRGs) are the largest individual objects in the Universe. To date, the reason why they reach such enormous extensions is still unclear. One of the proposed scenarios suggests that they are the result of multiple episodes of jet activity. Cross-correlating the INTEGRAL+Swift AGN population with radio catalogues (NVSS, FIRST, SUMSS), we found that 22% of the sources are GRG (a factor four higher than those selected from radio catalogues). Remarkably, all of the sources in the sample show signs of restarting radio activity. The X-ray properties are consistent with this scenario, the sources being in a high-accretion, high-luminosity state with respect to the previous activity responsible for the radio lobes.

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X-ray and γ-ray emissions from NLSy1 galaxies

International Journal of Modern Physics D ◽

10.1142/s0218271818440017 ◽

2018 ◽

Vol 27 (10) ◽

pp. 1844001 ◽

Cited By ~ 4

Author(s):

V. Baghmanyan ◽

N. Sahakyan

Keyword(s):

Spectral Properties ◽

Radio Galaxies ◽

Narrow Line ◽

High Luminosity ◽

Large Area ◽

X Ray ◽

Emission Properties ◽

Balmer Lines ◽

Γ Ray

The recent observations by Fermi large area telescope (Fermi-LAT) showed that in addition to the radio galaxies and blazars, Narrow-Line Seyfert 1 (NLSy1) galaxies are also [Formula: see text]-rays emitters. NLSy1 are AGNs with optical spectral properties similar to those of Seyfert 1 galaxies, except for having narrow Balmer lines and strong optical lines. They also exhibit strong X-ray variability, steep X-ray spectra and relatively high luminosity. The multiwavelength emission properties of 1H 0323+342, SBS 0846+513 and PMN J0948+0022 are discussed, using the [Formula: see text]-ray data from the last 8.8 years Fermi-LAT observations as well as available Swift(UVOT/XRT) data. It is shown that one-zone synchrotron/synchrotron self-Compton (SSC) model can satisfactorily reproduce their observed broadband spectra.

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The Unification of Radio-Loud AGN

Symposium - International Astronomical Union ◽

10.1017/s0074180900081158 ◽

1996 ◽

Vol 175 ◽

pp. 379-380

Author(s):

C. M. Urry ◽

Paolo Padovani

Keyword(s):

Uv Light ◽

Radio Galaxies ◽

Current Status ◽

High Luminosity ◽

Relativistic Jets ◽

Bl Lac Objects ◽

X Ray ◽

Relativistic Beaming ◽

Bl Lac ◽

Bl Lacs

In a recent review paper we summarized the current status of unification of radio-loud AGN (Urry & Padovani 1995 PASP 107, 803), connecting high-luminosity (FR II) radio galaxies with quasars, and low-luminosity (FR I) radio galaxies with BL Lac objects. Unified schemes are motivated by the knowledge that AGN appearance depends strongly on orientation (Fig. 1): optical/UV light from the centers of many AGN is obscured by circumnuclear matter, and in radio-loud AGN, bipolar relativistic jets beam light along the jet axes. Understanding these radiation anisotropics allows us to unify apparently distinct classes of AGN that differ primarily because of orientation.Our review described the classification and general properties of AGN and summarized the evidence for anisotropic emission caused by circumnuclear obscuration and relativistic beaming. We outlined the evidence, both observed isotropic properties and statistical arguments, for connecting FR IIs with quasars and FR Is with BL Lacs. The population statistics (with beaming) are in accordance with available data and suggest γ ≃ 5 for low-luminosity AGN and γ ≃ 10 for high-luminosity AGN. The distinctions between X-ray-selected and radio-selected BL Lac objects, and between BL Lacs and flat-spectrum variable quasars, still not understood, provide clues to the underlying physics of blazars. Our review discussed several possible problems and complications, and concluded with a list of the ten questions we believe are the most pressing in this field.

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Infrared Diagnostics of the ISM in the Circumnuclear Environments of the Youngest Radio Galaxies

Proceedings of the International Astronomical Union ◽

10.1017/s174392131800738x ◽

2018 ◽

Vol 14 (S342) ◽

pp. 268-269

Author(s):

E. Kosmaczewski ◽

Ł. Stawarz ◽

A. Wójtowicz

Keyword(s):

Galaxy Evolution ◽

Radio Galaxy ◽

Radio Galaxies ◽

Clear Correlation ◽

High Luminosity ◽

Systematic Analysis ◽

Mid Infrared ◽

X Ray ◽

Infrared Diagnostics ◽

Resolution Data

AbstractHere we present a systematic analysis of the mid-infrared properties of young radio galaxies, based on lower-resolution data provided by WISE and IRAS satellites. We restrict our analysis to sources in the earliest phase of radio galaxy evolution, with corresponding ages of the radio structures ≤ 3,000 yrs. In our sample of 29 objects, we find a variety of WISE colors, which suggests that the mid-infrared continua of studied sources are not exclusively contributed to by the circumnuclear dust. A comparison of the total mid-infrared and absorption-corrected X-ray luminosities for our sample reveals a clear correlation between the two bands. This favors the scenario in which the observed X-ray emission of young radio galaxies — at least the high-luminosity ones — originates predominantly in accretion disk corona.

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The intermediate-power population of radio galaxies: morphologies and interactions

Proceedings of the International Astronomical Union ◽

10.1017/s1743921319003533 ◽

2018 ◽

Vol 14 (A30) ◽

pp. 90-93

Author(s):

Diana M. Worrall ◽

Ryan T. Duffy ◽

Mark Birkinshaw

Keyword(s):

Luminosity Function ◽

Full Range ◽

Radio Galaxies ◽

Power Sources ◽

X Ray ◽

Power Injection ◽

Work Done ◽

The Universe ◽

Radio Luminosity Function ◽

Radio Power

AbstractRadio galaxies of intermediate power dominate the radio-power injection in the Universe as a whole, due to the break in the radio luminosity function, and so are of special interest. The population spans FR I, FR II, and hybrid morphologies, resides in a full range of environmental richness, and sources of all ages are amenable to study. We describe structures and interactions, with emphasis on sources with deep high-resolution Chandra X-ray data. As compared with low-power sources there is evidence that the physics changes, and the work done in driving shocks can exceed that in evacuating cavities. A range of morphologies and phenomena is identified.

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Quantiles as Robust Probes of Non-Gaussianity in 21-cm Images

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stab318 ◽

2021 ◽

Author(s):

Alon Banet ◽

Rennan Barkana ◽

Anastasia Fialkov ◽

Or Guttman

Keyword(s):

Galactic Halo ◽

Angular Resolution ◽

Research Effort ◽

First Stars ◽

X Ray ◽

Global Signal ◽

Radio Background ◽

Halo Masses ◽

The Universe ◽

Cosmic History

Abstract The epoch in which the first stars and galaxies formed is among the most exciting unexplored eras of the Universe. A major research effort is focused on probing this era with the 21-cm spectral line of hydrogen. While most research focuses on statistics like the 21-cm power spectrum or the sky-averaged global signal, there are other ways to analyze tomographic 21-cm maps, which may lead to novel insights. We suggest statistics based on quantiles as a method to probe non-Gaussianities of the 21-cm signal. We show that they can be used in particular to probe the variance, skewness, and kurtosis of the temperature distribution, but are more flexible and robust than these standard statistics. We test these statistics on a range of possible astrophysical models, including different galactic halo masses, star-formation efficiencies, and spectra of the X-ray heating sources, plus an exotic model with an excess early radio background. Simulating data with angular resolution and thermal noise as expected for the Square Kilometre Array (SKA), we conclude that these statistics can be measured out to redshifts above 20 and offer a promising statistical method for probing early cosmic history.

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IUE Studies of Luminous X-Ray Binaries

Highlights of Astronomy ◽

10.1017/s1539299600005736 ◽

1983 ◽

Vol 6 ◽

pp. 648-648

Author(s):

J.B. Hutchings

Keyword(s):

Magellanic Clouds ◽

Thick Shell ◽

High Luminosity ◽

Uv Spectrum ◽

X Ray ◽

Unique Object ◽

The Future ◽

Orbit Inclination ◽

Supercritical Accretion ◽

X Ray Binaries

IUE has been used to study 11 high luminosity X-ray binaries, of which 3 are in the Magellanic Clouds. In the supergiant systems, X-ray ionisation bubbles have been found in most cases, leading to a greater understanding of the winds and accretion processes. Further studies of precessing objects such as LMC X-4 with IUE and ST are clearly of considerable interest, relating to X-ray heating and blanketing. Detailed studies of the Cyg X-l ionisation bubble may resolve the long standing puzzle of its orbit inclination and masses. UV continua have furnished valuable information on extinction, temperatures and luminosities, and the presence of non-stellar (i.e. disk) luminosity. Here too, more detailed studies are clearly indicated for the future. A unique object of interest is the LMC transient 0538-66 whose UV spectrum has quasarlike lines and luminosity which varies oppositely to the visible. This may be a case of supercritical accretion generating an optically thick shell (“disk”) about the pulsar.

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The Voyage of Metals in the Universe from Cosmological to Planetary Scales: the need for a Very High-Resolution, High Throughput Soft X-ray Spectrometer

Experimental Astronomy ◽

10.1007/s10686-021-09710-2 ◽

2021 ◽

Author(s):

F. Nicastro ◽

J. Kaastra ◽

C. Argiroffi ◽

E. Behar ◽

S. Bianchi ◽

...

Keyword(s):

Chemical Composition ◽

High Resolution ◽

Deep Understanding ◽

High Resolution Spectroscopy ◽

X Ray ◽

Viable Solution ◽

Surrounding Space ◽

Nuclear Processes ◽

The Universe ◽

Very High

AbstractMetals form an essential part of the Universe at all scales. Without metals we would not exist, and the Universe would look completely different. Metals are primarily produced via nuclear processes in stars, and spread out through winds or explosions, which pollute the surrounding space. The wanderings of metals in-and-out of astronomical objects are crucial in determining their own evolution and thus that of the Universe as a whole. Detecting metals and assessing their relative and absolute abundances and energetics can thus be used to trace the evolution of these cosmic components. The scope of this paper is to highlight the most important open astrophysical problems that will be central in the next decades and for which a deep understanding of the Universe’s wandering metals, their physical and kinematical states, and their chemical composition represents the only viable solution. The majority of these studies can only be efficiently performed through High Resolution Spectroscopy in the soft X-ray band.

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The Hot Universe with XRISM and Athena

Proceedings of the International Astronomical Union ◽

10.1017/s1743921318007792 ◽

2018 ◽

Vol 14 (S342) ◽

pp. 29-36

Author(s):

M. Guainazzi ◽

M. S. Tashiro

Keyword(s):

Electromagnetic Radiation ◽

Large Scale ◽

Cosmological Evolution ◽

X Ray ◽

Hot Gas ◽

Cosmic Vision ◽

Esa Cosmic Vision ◽

The Universe

AbstractX-ray spectroscopy is key to address the theme of “The Hot Universe”, the still poorly understood astrophysical processes driving the cosmological evolution of the baryonic hot gas traceable through its electromagnetic radiation. Two future X-ray observatories: the JAXA-led XRISM (due to launch in the early 2020s), and the ESA Cosmic Vision L-class mission Athena (early 2030s) will provide breakthroughs in our understanding of how and when large-scale hot gas structures formed in the Universe, and in tracking their evolution from the formation epoch to the present day.

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