<i>XMM‐Newton</i>Observation of Solar Wind Charge Exchange Emission

Snowden, S. L.; Collier, M. R.; Küntz, K. D.

doi:10.1086/421841

Cited by 256 publications

(319 citation statements)

References 26 publications

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“…We checked the observation for contamination by solar wind charge exchange. The ACE SWEPAM 1 proton flux was less than 4 × 10 8 protons s −1 cm −2 which is typical of the quiescent Sun (e.g., Snowden et al 2004;Fujimoto et al 2007;Yoshino et al 2009), and the light curve accumulated in a 0.5−2 keV energy band (after soft proton flares removal) did not show any variability. The spectra of the out-of-field-of-view events of CCD 4 and 5 of MOS1 and CCD 5 of MOS 2 showed an anomalously high flux in the soft band (see ) so they were therefore excluded from our analysis.…”

Section: Observation and Data Reductionmentioning

confidence: 91%

Apparent high metallicity in 3–4 keV galaxy clusters: the inverse iron-bias in action in the case of the merging cluster Abell 2028

Gastaldello¹,

Ettori²,

Balestra³

et al. 2010

A&A

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Context. Recent work based on a global measurement of the ICM properties finds evidence for an increase in the iron abundance in galaxy clusters with temperatures around 2−4 keV up to a value about 3 times higher than is typical of very hot clusters Z Fe 0.25 Z . Aims. We have started a study of the metal distribution in nearby X-ray luminous poor galaxy clusters in the temperature range 3−4 keV with measured high abundances. Our study aims at spatially resolving the metal content of the central regions of the ICM, in particular characterizing how our measurements are biased by the diagnostics adopted and by the possible multi-temperature nature of the projected observed spectra. We report here on a 42 ks XMM-Newton observation of the first object in the sample, the cluster Abell 2028. Methods. We selected interesting regions of the ICM to analyze the spatially resolved structure of projected temperature and abundance, thereby producing two-dimensional maps. Results. The XMM-Newton observation of the first object of the sample, the cluster Abell 2028, reveals the complex structure of the cluster over a scale of ∼300 kpc, showing an interaction between two subclusters in cometary-like configurations. Cold fronts have been detected at the leading edges of the two substructures. The core of the main subcluster is likely hosting a cool corona. We show that a one-component fit for this region returns a biased high metallicity. The inverse iron bias is caused by the behavior of the fitting code in shaping the Fe-L complex. In the presence of a multi-temperature structure of the ICM, the best-fit metallicity turns out to be artificially higher when the projected spectrum is modeled with a single temperature component, while it is not related to the presence of both Fe-L and Fe-K emission lines in the spectrum. After accounting for the inverse iron bias, the overall abundance of the cluster is consistent with the one typical of hotter, more massive clusters. Conclusions. We caution against interpreting high abundances inferred when fitting a single thermal component to spectra derived from relatively large apertures in 3−4 keV clusters, because the inverse iron bias can be present. Most of the inferences trying to relate high abundances in 3−4 keV clusters to fundamental physical processes will probably have to be revised.

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Section: Observation and Data Reductionmentioning

confidence: 91%

Apparent high metallicity in 3–4 keV galaxy clusters: the inverse iron-bias in action in the case of the merging cluster Abell 2028

Gastaldello¹,

Ettori²,

Balestra³

et al. 2010

A&A

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“…Our treatment of the different background components builds directly on the work by De Luca & Molendi (2004), Snowden et al (2004Snowden et al ( , 2008; see also Snowden & Kuntz (2012).…”

Section: Figmentioning

confidence: 99%

The XMM deep survey in the CDF-S

Ranalli¹,

Comastri²,

Vignali³

et al. 2013

A&A

128

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Nuclear obscuration plays a key role in the initial phases of AGN growth, yet not many highly obscured active galactic nuclei (AGN) are currently known beyond the local Universe, and their search is an active topic of research. The XMM-Newton survey in the Chandra Deep Field South (XMM-CDFS) aims at detecting and studying the spectral properties of a significant number of obscured and Compton-thick (N H > ∼ 10 24 cm −2 ) AGN. The large effective area of XMM-Newton in the 2-10 and 5-10 keV bands, coupled with a 3.45 Ms nominal exposure time (2.82 and 2.45 Ms after light curve cleaning for MOS and PN, respectively), allows us to build clean samples in both bands, and makes the XMM-CDFS the deepest XMM-Newton survey currently published in the 5-10 keV band. The large multi-wavelength and spectroscopic coverage of the CDFS area allows for an immediate and abundant scientific return. In this paper, we present the data reduction of the XMM-CDFS observations, the method for source detection in the 2-10 and 5-10 keV bands, and the resulting catalogues. A number of 339 and 137 sources are listed in the above bands with flux limits of 6.6 × 10 −16 and 9.5× 10 −16 erg s −1 cm −2 , respectively. The flux limits at 50% of the maximum sky coverage are 1.8× 10 −15 and 4.0× 10 −15 erg s −1 cm −2 , respectively. The catalogues have been cross-correlated with the Chandra ones: 315 and 130 identifications have been found with a likelihood-ratio method, respectively. A number of 15 new sources, previously undetected by Chandra, is found; 5 of them lie in the 4 Ms area. Redshifts, either spectroscopic or photometric, are available for ∼95% of the sources. The number counts in both bands are presented and compared to other works. The survey coverage has been calculated with the help of two extensive sets of simulations, one set per band. The simulations have been produced with a newly-developed simulator, written with the aim of the most careful reproduction of the background spatial properties. For this reason, we present a detailed decomposition of the XMM-Newton background into its components: cosmic, particle, and residual soft protons. The three components have different spatial distributions. The importance of these three components depends on the band and on the camera; the particle background is the most important one (80-90% of the background counts), followed by the soft protons (4-20%).

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“…Snowden et al (2004) used a method to subtract the EPIC-MOS instrumental background by scaling closed filter observations, as created by the XMM-Newton science operations centre (SOC). Other authors Read & Ponman 2003;De Luca & Molendi 2004;Nevalainen et al 2005) developed and used comparable methods.…”

Section: Epic Backgroundmentioning

confidence: 99%

The metal contents of two groups of galaxies

Grange

Plaa

Kaastra

et al. 2011

A&A

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Context. The hot gas in clusters and groups of galaxies is continuously being enriched with metals from supernovae and stars. It is well established that the enrichment of the gas with elements from oxygen to iron is mainly caused by supernova explosions. The origins of nitrogen and carbon are still being debated. Possible candidates include massive, metal-rich stars, early generations of massive stars, intermediate-or low-mass stars and asymptotic giant branch (AGB) stars. Aims. In this paper we accurately determine the metal abundances of the gas in the groups of galaxies NGC 5044 and NGC 5813, and discuss the nature of the objects that create these metals. We mainly focus on carbon and nitrogen. Methods. We use spatially-resolved high-resolution X-ray spectroscopy from XMM-Newton. For the spectral fitting, multitemperature hot gas models are used. Results. The abundance ratios of carbon over oxygen and nitrogen over oxygen that we find are high compared to the ratios in the stars in the disk of our Galaxy. The oxygen and nitrogen abundances we derive are similar to what has been found in earlier work on other giant ellipticals in comparable environments. We show that the iron abundances in both our sources have a gradient along the cross-dispersion direction of the reflection grating spectrometer (RGS). Conclusions. We conclude that it is unlikely that the creation of nitrogen and carbon takes place in massive stars, which end their lives as core-collapse supernovae, enriching the medium with oxygen because oxygen should then also be enhanced. Therefore we favour low-and intermediate-mass stars as sources of these elements. The abundances in the hot gas can be explained best by a 30-40% contribution of type Ia supernovae based on the measured oxygen and iron abundances and under the assumption of a Salpeter initial mass function (IMF).

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XMM‐NewtonObservation of Solar Wind Charge Exchange Emission

Cited by 256 publications

References 26 publications

Apparent high metallicity in 3–4 keV galaxy clusters: the inverse iron-bias in action in the case of the merging cluster Abell 2028

Apparent high metallicity in 3–4 keV galaxy clusters: the inverse iron-bias in action in the case of the merging cluster Abell 2028

The XMM deep survey in the CDF-S

The metal contents of two groups of galaxies

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