A method for correcting aspect solution errors in ROSAT HRI observations of compact sources

Morse, Jon A.

doi:10.1086/133428

Cited by 36 publications

(39 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We find a systematic broadening of the radial source profile of order 1-3 in comparison with the core of the theoretical point spread function of the instrument. Such deviations have been observed previously in other sources, and can be traced back to instrumental effects (e.g., Morse 1994). Figure 2 provides a contour plot of the X-ray emission in the field around MR 2251-178.…”

Section: Spatial Analysissupporting

confidence: 71%

The X-ray view of the quasar MR 2251-178 and its host cluster: Variability, absorption, and intracluster gas emission

Komossa

2001

A&A

View full text Add to dashboard Cite

Abstract. MR 2251-178 was the first quasar initially discovered in X-rays, and the first one found to host a warm absorber. The quasar turned out to be an outstanding object in many respects. It has a high ratio of X-ray/optical luminosity, is surrounded by the largest quasar emission-line nebula known, and is located in the outskirts of a cluster of galaxies. Here, we present results from an analysis of the X-ray spectral, temporal, and spatial properties of this source and its environment based on deep ROSAT observations. Remarkably, we do not detect any excess X-ray cold absorption expected to originate from the giant gas nebula surrounding MR 2251-178. This excludes the presence of a huge HI envelope around the quasar. The X-ray spectrum of MR 2251-178 is best fit by a warmabsorbed powerlaw with an ionization parameter log U = 0.5 and a column density log Nw = 22.6 which, however, cannot be the same material as the giant optical emission line nebula. The mean (0.1-2.4) keV X-ray luminosity amounts to 10 45 erg/s. A spatial analysis shows that the bulk of the X-ray emission from the quasar is consistent with a point source, as expected in view of the powerlaw-shaped X-ray spectrum and the rapid X-ray variability we detect. In addition, extended emission appears at weak emission levels, including a bridge between the quasar and the cD galaxy of the cluster. The X-ray emission from the intra-cluster medium is weak or absent. We derive an upper limit on the X-ray luminosity of Lx ≤ 1.6 10 42 erg/s, weaker than other clusters of comparable richness. None of the other member galaxies of the cluster to which MR 2251-178 belongs, are detected in X-rays. However, east of the quasar there is a significant excess of X-ray sources, several of them without optical counterparts on the UK Schmidt plates.

show abstract

Section: Spatial Analysissupporting

confidence: 71%

The X-ray view of the quasar MR 2251-178 and its host cluster: Variability, absorption, and intracluster gas emission

Komossa

2001

A&A

View full text Add to dashboard Cite

show abstract

“…As errors in the ROSAT aspect solution can introduce spurious extension of up to about 10 arcsec (e.g. Morse 1994), these results are consistent with the source being unresolved. The upper limit then implies with a high degree of confidence that the X-ray emission comes from a region less than 14 kpc in size.…”

Section: C33supporting

confidence: 69%

Magnetic field strengths in the hotspots of 3C 33 and 111

Hardcastle

Birkinshaw

Worrall

1998

Monthly Notices RAS

View full text Add to dashboard Cite

We report on ROSAT HRI observations of the nearby powerful radio galaxies 3C 33 and 3C 111, which both have detected optical hot spots. We find nuclear X-ray sources in both objects, but no X-ray emission from the hot spots. This confirms the presence of a high-energy cutoff in the spectrum of synchrotron-emitting electrons. Since these electrons necessarily scatter the synchrotron photons by the inverse-Compton process, our upper limits on the X-ray fluxes of the hot spots allow us to set lower limits of a few nanotesla on their magnetic flux density, close to or greater than the fields implied by equipartition of energy between radiating particles and magnetic field.

show abstract

“…We note here that a 22.5 ks ROSAT HRI observation of MCG 6 30 15, after correction using the algorithm of Morse (1994), does not show any strong extended soft X-ray emission (Fig. 1), such as expected from a powerful out ow.…”

Section: Jets and Out Owsmentioning

confidence: 59%

On broad iron K <italic>α</italic> lines in seyfert 1 galaxies

1995

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

The X-ray spectrum obtained by Tanaka et al from a long observation of the active galaxy MCG 6 30 15 shows a broad iron K line skewed to low energies. The simplest interpretation of the shape of the line is that it is due to doppler and gravitational redshifts from the inner parts of a disk about a massive black hole. Similarly broad lines are evident in shorter observations of several other active galaxies. In this paper we investigate other line broadening and skewing mechanisms such as Comptonization in cold gas and doppler shifts from out ows. We have also tted complex spectral models to the data of MCG 6 30 15 to see whether the broad skewed line can be mimicked well by other absorption or emission features. No satisfactory mechanism or spectral model is found, thus strengthening the relativistic disk line model.

show abstract

A method for correcting aspect solution errors in ROSAT HRI observations of compact sources

Cited by 36 publications

References 4 publications

The X-ray view of the quasar MR 2251-178 and its host cluster: Variability, absorption, and intracluster gas emission

The X-ray view of the quasar MR 2251-178 and its host cluster: Variability, absorption, and intracluster gas emission

Magnetic field strengths in the hotspots of 3C 33 and 111

On broad iron K <italic>α</italic> lines in seyfert 1 galaxies

Contact Info

Product

Resources

About