CIAO: Chandra's data analysis system

Fruscione, A.; McDowell, Jonathan; Allen, G. E.; Brickhouse, N. S.; Burke, Douglas; Davis, John E.; Durham, Nick; Elvis, M.; Galle, Elizabeth C.; Harris, D. E.; Huenemoerder, David P.; Houck, J. C.; Ishibashi, Bish; Karovska, M.; Nicastro, F.; Noble, Michael S.; Nowak, Michael A.; Primini, F. A.; Siemiginowska, Aneta; Smith, Randall K.; Wise, Michael

doi:10.1117/12.671760

Cited by 1,038 publications

(364 citation statements)

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“…This further observation (ObsID 12834) added 13.6 ks to their sample. Starting from the raw files, we reprocessed all data using the standard tools available [32] in CIAO 4.5 and the latest version of the relevant calibration files, using the chandra repro script. Subpixel images were created for each observation and one such image is shown in Figure 1 of the main manuscript (observation made on November 28, 2009; Sequence Number 702126; Obs ID number 11540).…”

Section: Methods Summarymentioning

confidence: 99%

Reflection from the strong gravity regime in a lensed quasar at redshift z = 0.658

Reis

Reynolds

Miller

et al. 2014

Nature

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The co-evolution of a supermassive black hole with its host galaxy[1] through cosmic time is encoded in its spin[2, 3, 4]. At z > 2, supermassive black holes are thought to grow mostly by merger-driven accretion leading to high spin. However, it is unknown whether below z ∼ 1 these black holes continue to grow via coherent accretion or in a chaotic manner [5], though clear differences are predicted [3,4] in their spin evolution. An established method[6] to measure the spin of black holes is via the study of relativistic reflection features [7] from the inner accretion disk. Owing to their greater distances, there has hitherto been no significant detection of relativistic reflection features in a moderateredshift quasar. Here, we use archival data together with a new, deep observation of a gravitationally-lensed quasar at z = 0.658 to rigorously detect and study reflection in this moderate-redshift quasar. The level of relativistic distortion present in this reflection spectrum enables us to constrain the emission to originate within 3 gravitational radii from the black hole, implying a spin parameter a = 0.87 +0.08 −0.15 at the 3σ level of confidence and a > 0.66 at the 5σ level. The high spin found here is indicative of growth via coherent accretion for this black hole, and suggests that black hole growth between 0.5 z 1 occurs principally by coherent rather than chaotic accretion episodes. 1When optically-thick material, e.g. an accretion disc, is irradiated by hard X-rays, some of the flux is reprocessed into an additional 'reflected' emission component, which contains both continuum emission and atomic features. The most prominent signature of reflection from the inner accretion disc is typically the relativistic iron Kα line (6.4-6.97 keV; rest frame) [8] and the Compton reflection hump [7] often peaking at 20 − 30 keV (rest-frame). However, the deep gravitational potential and strong Doppler shifts associated with regions around black holes will also cause the forest of soft X-ray emission lines in the ∼ 0.7 − 2.0 keV range to be blended into a smooth emission feature, providing a natural explanation for the "soft-excess" observed in the X-ray spectra of nearby active galactic nuclei (AGNs) [9,10]. Indeed, both the iron line and the soft excess can be used to provide insight into the nature of the central black hole and to measure its spin [10]. Prior studies have revealed the presence of a soft-excess in 90% of quasars at[11, 12] z 1.7, and broad Fe-lines are also seen in 25% of these objects [11,13], suggesting that reflection is also prevalent in these distant AGNs. However, due to the inadequate S/N resulting from their greater distances, the X-ray spectra of these quasars were necessarily modeled using simple phenomenological parameterizations [12,14].Gravitational lensing offers a rare opportunity to study the innermost relativistic region in distant quasars [15,16], by acting as a natural telescope and magnifying the light from these sources. Quasars located between 0.5 z 1 are considerably ...

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Section: Methods Summarymentioning

confidence: 99%

Reflection from the strong gravity regime in a lensed quasar at redshift z = 0.658

Reis

Reynolds

Miller

et al. 2014

Nature

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“…All datasets were analysed with ciao 4.8 and caldb 4.7.2 supplied by the Chandra X-ray Center [35]. Level 1 event files were reprocessed for the latest gain and charge transfer inefficiency correction and then filtered to remove cosmic rays.…”

Section: Data Reductionmentioning

confidence: 99%

A new bound on axion-like particles

Marsh

Russell

Fabian

et al. 2017

J. Cosmol. Astropart. Phys.

146

126

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Axion-like particles (ALPs) and photons can quantum mechanically interconvert when propagating through magnetic fields, and ALP-photon conversion may induce oscillatory features in the spectra of astrophysical sources. We use deep (370 ks), short frame time Chandra observations of the bright nucleus at the centre of the radio galaxy M87 in the Virgo cluster to search for signatures of light ALPs. The absence of substantial irregularities in the X-ray power-law spectrum leads to a new upper limit on the photon-ALP coupling, g aγ : using a very conservative model of the cluster magnetic field consistent with Faraday rotation measurements from M87 and M84, we find g aγ < 2.6 × 10 −12 GeV −1 at 95% confidence level for ALP masses m a ≤ 10 −13 eV. Other consistent magnetic field models lead to stronger limits of g aγ 1.1-1.5 × 10 −12 GeV −1 . These bounds are all stronger than the limit inferred from the absence of a gamma-ray burst from SN1987A, and rule out a substantial fraction of the parameter space accessible to future experiments such as ALPS-II and IAXO.

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“…The Chandra observations log is reported in Table 1. We analysed these data using CIAO version 4.8 (Fruscione et al 2006), following the standard analysis threads. In order to apply the most recent calibration files (CALDB 4.7.0, Graessle et al 2006), we reprocessed the data from the three observations using the chandra_repro script 6 , and used this to produce data products following standard procedures.…”

Section: Chandramentioning

confidence: 99%

An atlas of exotic variability in IGR J17091−3624: a comparison with GRS 1915+105

Court

Altamirano

Pereyra

et al. 2017

Monthly Notices of the Royal Astronomical Society

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We performed an analysis of all RXTE observations of the Low Mass X-ray Binary and Black Hole Candidate IGR J17091-3624 during the 2011-2013 outburst of the source. By creating lightcurves, hardness-intensity diagrams and power density spectra of each observation, we have created a set of 9 variability 'classes' that phenomenologically describe the range of types of variability seen in this object. We compare our set of variability classes to those established by Belloni et al. (2000) to describe the similar behaviour of the LMXB GRS 1915+105, finding that some types of variability seen in IGR J17091-3624 are not represented in data of GRS 1915+105. We also use all available X-ray data of the 2011-2013 outburst of IGR J17091-3624 to analyse its longterm evolution, presenting the first detection of IGR J17091-3624 above 150 keV as well as noting the presence of 're-flares' during the latter stages of the outburst. Using our results we place new constraints on the mass and distance of the object, and find that it accretes at 33% of its Eddington limit. As such, we conclude that Eddingtonlimited accretion can no longer be considered a sufficient or necessary criterion for GRS 1915+105-like variability to occur in Low Mass X-Ray Binaries.

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CIAO: Chandra's data analysis system

Cited by 1,038 publications

References 1 publication

Reflection from the strong gravity regime in a lensed quasar at redshift z = 0.658

Reflection from the strong gravity regime in a lensed quasar at redshift z = 0.658

A new bound on axion-like particles

An atlas of exotic variability in IGR J17091−3624: a comparison with GRS 1915+105

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