ترغب بنشر مسار تعليمي؟ اضغط هنا

The Galaxy Cluster Pypeline for X-ray Temperature Maps: ClusterPyXT

72   0   0.0 ( 0 )
 نشر من قبل Brian Alden
 تاريخ النشر 2019
  مجال البحث فيزياء
والبحث باللغة English




اسأل ChatGPT حول البحث

ClusterPyXT is a new software pipeline to generate spectral temperature, X-ray surface brightness, pressure, and density maps from X-ray observations of galaxy clusters. These data products help elucidate the physics of processes occurring within clusters of galaxies, including turbulence, shock fronts, nonthermal phenomena, and the overall dynamics of cluster mergers. ClusterPyXT automates the creation of these data products with minimal user interaction, and allows for rapid analyses of archival data with user defined parameters and the ability to straightforwardly incorporate additional observations. In this paper, we describe in detail the use of this code and release it as an open source Python project on GitHub.

قيم البحث

اقرأ أيضاً

X-ray spectra of galaxy clusters are dominated by the thermal emission from the hot intracluster medium. In some cases, besides the thermal component, spectral models require additional components associated, e.g., with resonant scattering and charge exchange. The latter produces mostly underluminous fine spectral features. Detection of the extra components therefore requires high spectral resolution. The upcoming X-ray missions will provide such high resolution, and will allow spectroscopic diagnostics of clusters beyond the current simple thermal modeling. A representative science case is resonant scattering, which produces spectral distortions of the emission lines from the dominant thermal component. Accounting for the resonant scattering is essential for accurate abundance and gas motion measurements of the ICM. The high resolution spectroscopy might also reveal/corroborate a number of new spectral components, including the excitation by non-thermal electrons, the deviation from ionization equilibrium, and charge exchange from surface of cold gas clouds in clusters. Apart from detecting new features, future high resolution spectroscopy will also enable a much better measurement of the thermal component. Accurate atomic database and appropriate modeling of the thermal spectrum are therefore needed for interpreting the data.
We present intensive quasi-simultaneous X-ray and radio monitoring of the narrow line Seyfert 1 galaxy NGC 4051, over a 16 month period in 2000-2001. Observations were made with the Rossi Timing X-ray Explorer (RXTE) and the Very Large Array (VLA) at 8.4 and 4.8 GHz. In the X-ray band NGC 4051 behaves much like a Galactic black hole binary (GBH) system in a `soft-state. In such systems, there has so far been no firm evidence for an active, radio-emitting jet like those found in `hard state GBHs. VLBI observations of NGC 4051 show three co-linear compact components. This structure resembles the core and outer hot spots seen in powerful, jet-dominated, extragalactic radio sources and suggests the existence of a weak jet. Radio monitoring of the core of NGC 4051 is complicated by the presence of surrounding extended emission and by the changing array configurations of the VLA. Only in the A configuration is the core reasonably resolved. We have carefully removed the contaminations of the core by extended emission in the various arrays. The resulting lightcurve shows no sign of large amplitude variability (i.e. factor 50 %) over the 16 month period. Within the most sensitive configuration (A array) we see marginal evidence for radio core variability of ~25% (~0.12 mJy at 8.4GHz) on a 2-week timescale, correlated with X-ray variations. Even if the radio variations in NGC 4051 are real, the percentage variability is much less than in the X-ray band. Within the B configuration observations, where sensitivity is reduced, there is no sign of correlated X-ray/radio variability. The lack of radio variability in NGC 4051, which we commonly see in `hard state GBHs, may be explained by orientation effects. Another possibility is that the radio emission arises from the X-ray corona, although the linear structure of the compact radio components here is hard to explain.
119 - A. D. Goulding 2012
We present the X-ray point-source catalog produced from the Chandra Advanced CCD Imaging Spectrometer (ACIS-I) observations of the combined sim3.2 deg2 DEEP2 (XDEEP2) survey fields, which consist of four ~0.7-1.1 deg2 fields. The combined total expos ures across all four XDEEP2 fields range from ~10ks-1.1Ms. We detect X-ray point-sources in both the individual ACIS-I observations and the overlapping regions in the merged (stacked) images. We find a total of 2976 unique X-ray sources within the survey area with an expected false-source contamination of ~30 sources (~1%). We present the combined logN-logS distribution of sources detected across the XDEEP2 survey fields and find good agreement with the Extended Chandra Deep Field and Chandra-COSMOS fields to f_{X,0.5-2keV}sim2x10^{-16} erg/cm^2/s. Given the large survey area of XDEEP2, we additionally place relatively strong constraints on the logN-logS distribution at high fluxes (f_{X,0.5-2keV}sim3x10^{-14} erg/cm^2/s), and find a small systematic offset (a factor ~1.5) towards lower source numbers in this regime, when compared to smaller area surveys. The number counts observed in XDEEP2 are in close agreement with those predicted by X-ray background synthesis models. Additionally, we present a Bayesian-style method for associating the X-ray sources with optical photometric counterparts in the DEEP2 catalog (complete to R_AB < 25.2) and find that 2126 (~71.4pm2.8%) of the 2976 X-ray sources presented here have a secure optical counterpart with a <6% contamination fraction. We provide the DEEP2 optical source properties (e.g., magnitude, redshift) as part of the X-ray-optical counterpart catalog.
Fluctuations of the surface brightness of cosmic X-ray background (CXB) carry unique information about faint and low luminosity source populations, which is inaccessible for conventional large-scale structure (LSS) studies based on resolved sources. We used Chandra data of the XBOOTES field ($sim9,mathrm{deg^2}$) to conduct the most accurate measurement to date of the power spectrum of fluctuations of the unresolved CXB on the angular scales of $sim3,$arcsec $-$ $sim17,$arcmin. We find that at sub-arcmin angular scales, the power spectrum is consistent with the AGN shot noise, without much need for any significant contribution from their one-halo term. This is consistent with the theoretical expectation that low-luminosity AGN reside alone in their dark matter halos. However, at larger angular scales we detect a significant LSS signal above the AGN shot noise. Its power spectrum, obtained after subtracting the AGN shot noise, follows a power law with the slope of $-0.8pm0.1$ and its amplitude is much larger than what can be plausibly explained by the two-halo term of AGN. We demonstrate that the detected LSS signal is produced by unresolved clusters and groups of galaxies. For the flux limit of the XBOOTES survey, their flux-weighted mean redshift equals $left<zright>sim0.3$, and the mean temperature of their intracluster medium (ICM), $left<Tright>approx 1.4$ keV, corresponds to the mass of $M_{500} sim 10^{13.5},mathrm{M}_odot$. The power spectrum of CXB fluctuations carries information about the redshift distribution of these objects and the spatial structure of their ICM on the linear scales of up to $sim$Mpc, i.e. of the order of the virial radius.
We present LOFAR $120-168$ MHz images of the merging galaxy cluster Abell 1240 that hosts double radio relics. In combination with the GMRT $595-629$ MHz and VLA $2-4$ GHz data, we characterised the spectral and polarimetric properties of the radio e mission. The spectral indices for the relics steepen from their outer edges towards the cluster centre and the electric field vectors are approximately perpendicular to the major axes of the relics. The results are consistent with the picture that these relics trace large-scale shocks propagating outwards during the merger. Assuming diffusive shock acceleration (DSA), we obtain shock Mach numbers of $mathcal{M}=2.4$ and $2.3$ for the northern and southern shocks, respectively. For $mathcal{M}lesssim3$ shocks, a pre-existing population of mildly relativistic electrons is required to explain the brightness of the relics due to the high ($>10$ per cent) particle acceleration efficiency required. However, for $mathcal{M}gtrsim4$ shocks the required efficiency is $gtrsim1%$ and $gtrsim0.5%$, respectively, which is low enough for shock acceleration directly from the thermal pool. We used the fractional polarization to constrain the viewing angle to $geqslant(53pm3)^circ$ and $geqslant(39pm5)^circ$ for the northern and southern shocks, respectively. We found no evidence for diffuse emission in the cluster central region. If the halo spans the entire region between the relics ($sim1.8,text{Mpc}$) our upper limit on the power is $P_text{1.4 GHz}=(1.4pm0.6)times10^{23},text{W}text{Hz}^{-1}$ which is approximately equal to the anticipated flux from a cluster of this mass. However, if the halo is smaller than this, our constraints on the power imply that the halo is underluminous.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا