Context. The diffuse X-ray emission surrounding radio galaxies is generally interpreted either as due to inverse Compton scattering of non-thermal radio-emitting electrons on the Cosmic Microwave ...Background (IC/CMB), or as the thermal emission arising from the hot gas of the intergalactic medium (IGM) permeating galaxy clusters hosting such galaxies, or as a combination of both. In this work we present an imaging and spectral analysis of Chandra observations for the radio galaxy 3C 187 to investigate its diffuse X-ray emission and constrain the contribution of these different physical mechanisms. Aims. The main goals of this work are: (i) to evaluate the extension of the diffuse X-ray emission from this source, (ii) to investigate the two main processes that can account for its origin - IC/CMB and thermal emission from the IGM - and (iii) to test the possibility for 3C 187 to belong to a cluster of galaxies, that can account for the observed diffuse X-ray emission. Methods. To evaluate the extension of the X-ray emission around 3C 187 we extracted surface flux profiles along and across the radio axis. We also extracted X-ray spectra in the region of the radio lobes and in the cross-cone region to estimate the contribution of the non-thermal (IC/CMB) and thermal (IGM) processes to the observed emission, making use of radio (VLA and GMRT) data to investigate the multi-wavelength emission arising from the lobes. We collected Pan-STARRS photometric data to investigate the presence of a galaxy cluster hosting 3C 187, looking for the presence of a "red sequence" in the source field in the form of a tight clustering of the galaxies in the color space...
We present the analysis of multi-wavelength observations of seven extragalactic radio sources, listed as unidentified in the Third Cambridge Revised Catalog (3CR). X-ray observations, performed ...during Chandra Cycle 21, were compared to VLA, WISE and Pan-STARRS observations in the radio, infrared and optical bands, respectively. All sources in this sample lack a clear optical counterpart, and are thus missing their redshift and optical classification. In order to confirm the X-ray and infrared radio counterparts of core and extended components, here we present for the first time radio maps obtained manually reducing VLA archival data. As in previous papers on the Chandra X-ray snapshot campaign, we report X-ray detections of radio cores and two sources, out of the seven presented here, are found to be members of galaxy clusters. For these two cluster sources (namely, 3CR 409 and 3CR 454.2), we derived surface brightness profiles in four directions. For all seven sources, we measured X-ray intensities of the radio sources and we also performed standard X-ray spectral analysis for the four sources (namely, 3CR 91, 3CR 390, 3CR 409 and 3CR 428) with the brightest nuclei (more than 400 photons in the 2'' nuclear region). We also detected extended X-ray emission around 3CR 390 and extended X-ray emission associated with the northern jet of 3CR 158. This paper represents the first attempt to give a multi-wavelength view of the unidentified radio sources listed in the 3CR catalog.
We present the analysis of X-ray and optical observations of gas filaments observed in the radio source 3CR 318.1, associated with NGC 5920, the Brightest Cluster Galaxy (BCG) of MKW 3s, a nearby ...cool core galaxy cluster. This work is one of the first X-ray and optical analyses of filaments in cool core clusters carried out using MUSE observations. We aim at identifying the main excitation processes responsible for the emission arising from these filaments. We complemented the optical VLT/MUSE observations, tracing the colder gas phase, with X-ray \(\textit{Chandra}\) observations of the hotter highly ionized gas phase. Using the MUSE observations, we studied the emission line intensity ratios along the filaments to constrain the physical processes driving the excitation, and, using the \(\textit{Chandra}\) observations, we carried out a spectral analysis of the gas along these filaments. We found a spatial association between the X-ray and optical morphology of these filaments, which are colder and have lower metal abundance than the surrounding intra-cluster medium (ICM), as already seen in other BCGs. Comparing with previous results from the literature for other BCGs, we propose that the excitation process that is most likely responsible for these filaments emission is a combination of star formation and shocks, with a likely contribution from self-ionizing, cooling ICM. Additionally, we conclude that the filaments most likely originated from AGN-driven outflows in the direction of the radio jet.
2018 ApJS, 234, 7 This paper presents the analysis of Chandra X-ray snapshot observations of a
subsample of the extragalactic sources listed in the revised Third Cambridge
radio catalog (3CR), ...previously lacking X-ray observations and thus observed
during Chandra Cycle 15. This data set extends the current Chandra coverage of
the 3CR extragalactic catalog up to redshift $z$=1.0. Our sample includes 22
sources consisting of one compact steep spectrum (CSS) source, three quasars
(QSOs), and 18 FR\,II radio galaxies. As in our previous analyses, here we
report the X-ray detections of radio cores and extended structures (i.e.,
knots, hotspots and lobes) for all sources in the selected sample. We measured
their X-ray intensities in three energy ranges: soft (0.5--1 keV), medium (1--2
keV) and hard (2-7 keV) and we also performed standard X-ray spectral analysis
for brighter nuclei. All radio nuclei in our sample have an X-ray counterpart.
We also discovered X-ray emission associated with the eastern knot of 3CR\,154,
with radio hotspots in 3CR\,41, 3CR\,54 and 3CR\,225B and with the southern
lobe of 3CR\,107. Extended X-ray radiation around the nuclei 3CR\,293.1 and
3CR\,323 on a scale of few tens kpc was also found. X-ray extended emission,
potentially arising from the hot gas in the intergalactic medium and/or due to
the high energy counterpart of lobes, is detected for 3CR\,93, 3CR\,154,
3CR\,292 and 3CR\, 323 over a few hundreds kpc-scale. Finally, this work also
presents an update on the state-of-the-art of Chandra and XMM-Newton
observations for the entire 3CR sample.
2018 ApJS, 235, 32 The aim of this paper is to present an analysis of newly acquired X-ray
observations of 16 extragalactic radio sources, listed in the Third Cambridge
Revised (3CR) catalog, and not ...previously observed by Chandra. Observations
were performed during Chandra Cycle 17, extending X-ray coverage for the 3CR
extragalactic catalog up to $z$=1.5. Among the 16 targets, two lie at $z<$0.5
(i.e., 3CR27, at $z$=0.184 and 3CR69, at $z$=0.458), all the remaining 14 have
redshifts between 1.0 and 1.5. In the current sample there are three compact
steep spectrum (CSS) sources, three quasars and an FRI radio galaxy, while the
other nine are FRII radio galaxies. All radio sources have an X-ray
counterpart. We measured nuclear X-ray fluxes as well as X-ray emission
associated with radio jet knots, hotspots or lobes in three energy bands: soft
(0.5-1 keV), medium (1-2 keV) and hard (2-7 keV). We also performed standard
X-ray spectral analysis for the four brightest nuclei. We discovered X-ray
emission associated with: the radio lobe of 3CR124; a hotspot of the quasar
3CR220.2; another hotspot of the radio galaxy 3CR238; and the jet knot of
3CR297. We also detected extended X-ray emission around the nuclear region of
3CR124 and 3CR297 on scales of several tens of kpc. Finally, we present an
update on the X-ray observations performed with Chandra and XMM-Newton on the
entire 3CR extragalactic catalog.
We present a multifrequency analysis of the radio galaxy 3CR 196.1 (\(z = 0.198\)), associated with the brightest galaxy of the cool core cluster CIZAJ0815.4-0303. This nearby radio galaxy shows a ...hybrid radio morphology and an X-ray cavity, all signatures of a turbulent past activity, potentially due to merger events and AGN outbursts. We present results of the comparison between \(Chandra\) and VLT/MUSE data for the inner region of the galaxy cluster, on a scale of tens of kpc. We discovered H\(\alpha\) + N II\(\lambda6584\) emission spatially associated with the X-ray cavity (at \(\sim\)10 kpc from the galaxy nucleus) instead of with its rim. This result differs from previous discoveries of ionized gas surrounding X-ray cavities in other radio galaxies harbored in galaxy clusters and could represent the first reported case of ionized gas filling an X-ray cavity, either due to different AGN outbursts or to the cooling of warm (\(10^4<T\leq10^7\) K) AGN outflows. We also found that the H\(\alpha\), N II\(\lambda\lambda6548,6584\) and S II\(\lambda\lambda6718,6733\) emission lines show an additional redward component, at \(\sim\)1000 km\(\,\)s\(^{-1}\) from rest frame, with no detection in H\(\beta\) or O III\(\lambda\lambda4960,5008\). We believe the most likely explanation for this redward component is the presence of a background gas cloud since there appears to be a discrete difference in velocities between this component and the rest frame.
We present the analysis of nine radio sources belonging to the Third Cambridge Revised catalog (3CR) observed with \(Chandra\) during Cycle 20 in the redshift range between 1.5 and 2.5. This study ...completes the 3CR \(Chandra\) Snapshot Survey thus guaranteeing the X-ray coverage of all 3CR sources identified to date. This sample lists two compact steep spectrum sources, four radio galaxies and three quasars. We detected X-ray emission from all nuclei, with the only exception of 3C 326.1 and 3C 454.1 and from radio lobes in 6 out of 9 sources at level of confidence larger than \(\sim\)5\(\sigma\). We measured X-ray fluxes and luminosities for all nuclei and lobes in the soft (0.5 - 1 keV), medium (1 - 2 keV) and hard (2 - 7 keV) X-ray bands. Since the discovered X-ray extended emission is spatially coincident with the radio structure in all cases, its origin could be due to Inverse Compton scattering of the Cosmic Microwave Background (IC/CMB) occurring in radio lobes.
This paper presents the analysis of Chandra X-ray snapshot observations of a subsample of the extragalactic sources listed in the revised Third Cambridge radio catalog (3CR), previously lacking X-ray ...observations and thus observed during Chandra Cycle 15. This data set extends the current Chandra coverage of the 3CR extragalactic catalog up to redshift \(z\)=1.0. Our sample includes 22 sources consisting of one compact steep spectrum (CSS) source, three quasars (QSOs), and 18 FR\,II radio galaxies. As in our previous analyses, here we report the X-ray detections of radio cores and extended structures (i.e., knots, hotspots and lobes) for all sources in the selected sample. We measured their X-ray intensities in three energy ranges: soft (0.5--1 keV), medium (1--2 keV) and hard (2-7 keV) and we also performed standard X-ray spectral analysis for brighter nuclei. All radio nuclei in our sample have an X-ray counterpart. We also discovered X-ray emission associated with the eastern knot of 3CR\,154, with radio hotspots in 3CR\,41, 3CR\,54 and 3CR\,225B and with the southern lobe of 3CR\,107. Extended X-ray radiation around the nuclei 3CR\,293.1 and 3CR\,323 on a scale of few tens kpc was also found. X-ray extended emission, potentially arising from the hot gas in the intergalactic medium and/or due to the high energy counterpart of lobes, is detected for 3CR\,93, 3CR\,154, 3CR\,292 and 3CR\, 323 over a few hundreds kpc-scale. Finally, this work also presents an update on the state-of-the-art of Chandra and XMM-Newton observations for the entire 3CR sample.
The aim of this paper is to present an analysis of newly acquired X-ray observations of 16 extragalactic radio sources, listed in the Third Cambridge Revised (3CR) catalog, and not previously ...observed by Chandra. Observations were performed during Chandra Cycle 17, extending X-ray coverage for the 3CR extragalactic catalog up to \(z\)=1.5. Among the 16 targets, two lie at \(z<\)0.5 (i.e., 3CR27, at \(z\)=0.184 and 3CR69, at \(z\)=0.458), all the remaining 14 have redshifts between 1.0 and 1.5. In the current sample there are three compact steep spectrum (CSS) sources, three quasars and an FRI radio galaxy, while the other nine are FRII radio galaxies. All radio sources have an X-ray counterpart. We measured nuclear X-ray fluxes as well as X-ray emission associated with radio jet knots, hotspots or lobes in three energy bands: soft (0.5-1 keV), medium (1-2 keV) and hard (2-7 keV). We also performed standard X-ray spectral analysis for the four brightest nuclei. We discovered X-ray emission associated with: the radio lobe of 3CR124; a hotspot of the quasar 3CR220.2; another hotspot of the radio galaxy 3CR238; and the jet knot of 3CR297. We also detected extended X-ray emission around the nuclear region of 3CR124 and 3CR297 on scales of several tens of kpc. Finally, we present an update on the X-ray observations performed with Chandra and XMM-Newton on the entire 3CR extragalactic catalog.
Bruton's tyrosine kinase (BTK) is essential for B-cell proliferation/differentiation and it is generally believed that its expression and function are limited to bone marrow-derived cells. Here, we ...report the identification and characterization of p65BTK, a novel isoform abundantly expressed in colon carcinoma cell lines and tumour tissue samples. p65BTK protein is expressed, through heterogeneous nuclear ribonucleoprotein K (hnRNPK)-dependent and internal ribosome entry site-driven translation, from a transcript containing an alternative first exon in the 5'-untranslated region, and is post-transcriptionally regulated, via hnRNPK, by the mitogen-activated protein kinase (MAPK) pathway. p65BTK is endowed with strong transforming activity that depends on active signal-regulated protein kinases-1/2 (ERK1/2) and its inhibition abolishes RAS transforming activity. Accordingly, p65BTK overexpression in colon cancer tissues correlates with ERK1/2 activation. Moreover, p65BTK inhibition affects growth and survival of colon cancer cells. Our data reveal that BTK, via p65BTK expression, is a novel and powerful oncogene acting downstream of the RAS/MAPK pathway and suggest that its targeting may be a promising therapeutic approach.
PDF