Tuesday, January 30, 2007

r1mach routine in xspec v11

An internal change to allow compilation using gfortran : the fortran r1mach routine which was included in the file functions/cont.f has been replaced by a C version (with appropriate cfortran macro) in the new file functions/r1mach.c. This should have no effect visible to users. The analogous change has already been made in v12.

Keywords: HEAsoft, xspec

Thursday, January 25, 2007

chatter in xselect

Binbin Zhang asks a question about using chatter in xselect. The chatter command is handled through the xpi gtcom2 call but was not defined in xselect.key and xselect.kw so was rejected as an unknown command. Modified these files so that chatter is now recognised. However, all output from xselect is at chatter=5 so unless we make changes to the xselwrite calls we can either see all the output or none of it.

Keywords: xselect, HEAsoft


Roncarelli et al. calculate the thermal and kinetic SZ signals from a large cosmology simulation and look at correlations with the soft X-ray signal.

Bolton et al. use strong lensing data to replace the surface brightness with mass density in the fundamental plane relation for ellipticals and show that the variance decreases and the tilt is removed implying that early type galaxies are an homologous sequence varying in mass-to-light ratio.

Mathews & Brighenti describe how cosmic rays produced by an AGN generate the cavities and radio sources seen in X-ray emitting clusters.

Edmondson et al. discuss frequentist and Bayesian estimation of photometric redshifts.

Krivinos et al. present results from the Integral/IBIS all-sky survey in the 17-60 keV band.

Ghosh & Raychaudhuri discuss the effect of systematic errors on time series data.

Shaw et al. describe a more efficient scheme for Bayesian inference in cosmology and make available their code.

Kalirai et al. use HST images to measure the proper motion of the globular cluster NGC6397 with respect to the population of background galaxies in the field.

Markevitch & Vihklinin review shocks and cold fronts in the ICM.

Friday, January 12, 2007

Old PS driver

At Andy Beardmore's suggestion put old PS driver back into the distribution available as /OPS, /OVPS, /OCPS, /OVCPS plot types.

Keywords: HEAsoft, pgplot

nsa model in xspec

Slava Zavlin supplied updated versions of the files used by the nsa model. These files are identical to the current versions except that the energy range is extended to 12 keV.

Keywords: HEAsoft, xspec

Thursday, January 11, 2007


Koester et al. create a catalog of 13,823 clusters of galaxies in the SDSS. The algorithm used is described in another preprint.

Collister et al. use a neural network to generate a photometric redshift catalog of over one million luminous red galaxies from the SDSS. The training set is a 15,000 galaxy spectroscopic catalog from Cannon et al.

Houck & Allen describe models for non-thermal photon emission.

Sato et al. measure temperature and abundance profiles in A1060 using Suzaku.

Done & Nayakshin argue that the AGN soft excess is more likely to be due to absorption in a wind than reflection from a disk since the latter, unlike the former, requires fine tuning of the ionization state.

Temi et al. find extended far IR emission from ellipticals using Spitzer and interpret it as due to cold gas buoyantly transported from a reservoir in the core.

Corasaniti et al. note that a new generation of big telescopes and very high resolution spectrographs will be able to measure the change in redshift in quasar absorption line systems over a ten-year baseline and hence constrain models for the cosmic expansion history.

Blasi et al. review expected gamma-ray emission from clusters of galaxies.

Kocsis et al. provide a Fourier decomposition method of determining the position of SMBH binary inspiral observed using LISA.

Ng argues that if spacetime undergoes quantum fluctuations then an EM wavefront acquires uncertainties in direction which will show up in interferometric observations of distant quasars.

Poole et al. use a suite of simulations to investigate the effects of mergers on cluster parameter relations.

de Plaa et al. use XMM observations of abundances in 22 clusters to test SN models.

Sesana et al. consider the prospects for using LISA observations to constrain models of the build-up of SMBHs.

Wednesday, January 10, 2007

bug in rbnrmf

Stephane Paltani reports an array overwrite warning message when running rbnrmf on JEM-X response matrix. It turns out to be due to these matrices having a starting channel of 0 for the EBD extension but 1 for the MATRIX extension. This shouldn't be a problem except that rbnrmf was incorrectly using the number from the EBD extension when rebinning the data from the MATRIX extension. Fixed this as version 5.0.1.

Keywords: HEAsoft, Integral

Monday, January 08, 2007


Bauer et al. use XMM RGS and EPIC observations to investigate the starburst outflow from NGC253. They use cross-dispersion profiles to map the distribution of prominent ions.

Dimopolous et al. propose various laboratory tests of GR using atom interferometry.

Liddle et al. discusses Bayesian evidence for techniques for dark energy.

Petrosian et al. report on RXTE observations of the "bullet cluster".

Clowe et al. present weak lensing results on the cluster 1E0657-558 which shows that the baryon (X-ray emitting) peak is not at the same position as the dark matter peak.

Wheatley & Kallman note the striking similarity between the X-ray spectra of the symbiotic star CH Cyg and Seyfert II - the soft component in both is due to scattering off a photoionized medium.

Dravina reviews quantum optical effects which may be of interest in astronomy.

Ford & Gregory discuss Bayesian model selection in planet searches.

Coble et al. present results on 28.5 GHz radio sources in 90 cluster fields. They find 9 times more sources in cluster cores than in the outskirts which themselves are 3 times overdense in sources relative to the field.

Barnes et al. present the S2PLOT 3-D graphics library.

Churazov et al. use Earth-occulting INTEGRAL observations to measure the CXB from 5-100 keV. They find results consistent to HEAO-1 but with a 10% higher normalization.

Wednesday, January 03, 2007

cstat with background files and low counts

There are bugs in both v11 and v12 which prevent correct convergence for some datasets with low counts in both the source and background files. The v11 fix is available as 11.3.2ab and the v12 fix will be available shortly.

However, it appears that the eventual best fit is still biased - this is likely a statistical rather than computational problem. The model seems to be be biased systematically below the data so a possible approach is to add another term which pushes the total number of model and data counts to be the same.

Keywords: HEAsoft, xspec

Monday, January 01, 2007


Gruzinov estimates molecular viscosity in the ICM due to magnetic fields and finds a value large enough to noticeably damp turbulence.

von der Linden et al. construct a sample of 625 brights group and cluster galaxies from the SDSS and compare their properties with other ellipticals.

Best et al. use their sample of BCGs to show that BCGs are preferentially radio-loud and consider the consequences for cooling cores.

Pfrommer et al. calculate the effects of cosmic rays on the X-ray luminosity and S-Z decrement of clusters of galaxies.

Mix et al. present a primer on astrobiology.

Gilli et al. detail their latest CXB synthesis.

Scargle et al. discuss the problem of testing quantum gravity with timing data on GRBs.

Liddle reviews approaches to the problem of selecting between competing models.

Takei et al. claim a detection of the WHIM in the direction of X Comae both in absorption using the XMM RGS and emission using EPIC.

Nevaleinen et al. look at XMM observations of 4 clusters with previous claims of soft excesses and conclude that there are still significant calibration problems at low energies in either the MOS or PN (or perhaps) both which make it impossible to conclude whether or not there is a soft excess.

Kallman & Palmeri review atomic data sources of relevance for astronomy.