chandra response matrix generation in xselect

Updated the perl script xsl_chandra_acis_makeresp to replace old ftools with new heatools and improve the search for the bad pixel file. Outstanding issues are that mkacisrmf doesn't work with old event files (fails to find a relevant CALDB file) presumably because these event files have to be reprocessed in CIAO 3.4; the current advice is to use mkarf for point sources and mkwarf for extended sources - at present we use mkwarf for all sources; there should be a mechanism for the user to give their own bad pixel file.

bug in kerrbb

There is a memory handling bug in kerrbb (due to my error) which can cause a seg fault if multiple response matrices are in use and the first one does not have the largest number of energy bins. This is fixed in both v11 and v12.

filter intensity in xselect

Another iteration on the filter intensity perl script in xselect. Replaced most of the calls to old ftools with their heatools analogs. This seems to fix a problem with long filenames.

bug in extractor when combining event files

Fixed bug reported by Phil Evans when creating a new event file from multiple input event files with different WCS values. If the sky X and Y columns were integers the new values were calculated as an INT after doing the transformation instead of a NINT causing a possible one pixel shift. Also did some optimization of the code. v4.74.

Update: Also found that the goodfwcs logical variable in EXTWCS was not being initialized which was causing the position recalculation not to occur in some circumstances. v4.75

Keywords: HEAsoft, extractor.

xspec error with the migrad method

There was a bug in xspec v12 when using the error command with the migrad method. If there were frozen parameters the wrong parameter number was being passed to the MINOS command.

A useful tip to know when using migrad is that the standard MINUIT output is written to the file mn_output.log in the current directory.

Handy C++ tip: there is a function, distance, associated with maps to return the distance in the first index of the map between two iterators. So if we have a map called mymap and an iterator called iter then the position in the map list of iter is 1+distance(mymap.begin(),iter).

Keywords: HEAsoft, xspec

keV-Angstrom conversion factor in xspec

Both v11 and v12 xspec use a conversion factor from keV to Angstrom of 12.39854. Using the current standard values of constants (CODATA(2002) via NIST) this factor should be 12.3984191. Apparently the difference is noticeable when plotting grating spectra in wavelengths. Made this change in both v11 (bug fix 11.3.2ac) and v12.

Keywords: HEAsoft, xspec

text size in the PGPLOT PS driver

Another tweak of the new PGPLOT PS driver to get the text size closer to that appearing on the screen with other drivers. Also, moved the code to calculate the correction to the string length from grlen to the driver.

Keywords: HEAsoft, pgplot

ranlux in xspec11

xspec11 crashes when compiled using gfortran apparently due to a problem with ranlux. So replaced xanlib/sysdep/ranlux.f with C code based on the gsl version but with gsl-specific parts stripped out. Note that only the RLUXGO and RANLUX Fortran calls are supported and that RLUXGO ignores the final two arguments (K1 and K2) ie the restart option is not supported.

Keywords: HEAsoft, xspec

Preprints

Portegies Swart et al. test using modern Graphics Processing Units to perform N-body calculations and conclude they show some cost and reliability benefits over specialised hardware.

Brownstein & Moffatt argue that the bullet cluster results are consistent with modified gravity and not with dark matter.

Evrard et al. use an ensemble of heirarchical clustering simulations to argue that sigma_8 = 0.8 in contrast to the best-fit number of 0.69 favored by recent WMAP and SDSS analysis.

Lodato & Natarajan derive the seed function of mass BHs at z~15.

Krongold et al. use an XMM observation of NGC4051 to track changes in the ionization state of the warm absorber and deduce that it comes from an accretion disk wind not the dusty torus.

Schafer provides a statistically rigorous method of estimating luminosity function using truncated data.

Rossetti & Molendi fire back in the controversy over the existence of a non-thermal tail in the X-ray spectrum of the Coma cluster.

Medvedev examines evaporation rates of hot gas from clusters as a possible explanation of recent S-Z results and concludes that for the mechanism to work magnetic fields must be non-existent or highly ordered.

Seto & Cooray discuss a technique for placing limits on primordial BH densities by using pulsar timing measurements to look for impulsive accelerations on the Earth.

Linder & Miquel warn against applying model selection procedures in cosmology without adequate thought about physics.

Hickox & Markevitch look at Chandra deep field data excluding all known HST and Spitzer sources to provide a limit on X-ray emission from the WHIM.

Fusco-Femiano et al. continue the data about the Coma hard X-ray emission.

Chen et al. use ROSAT and ASCA observations of HIFLUGCS clusters to investigate the statistical properties of cooling cores.

Zavlin reviews what is known about thermal emission from neutron stars.

Johnstone et al. analyze the Spitzer 10-37 micron spectra from off-nuclear regions in NGC1275 and 4696.

extractor and string columns

Phil Evans reported a problem that when combining two event files a string column in the output was garbage for all rows copied from the second input file. This happened because the input files had differing WCS so the slow copy method had to be used and this read all columns as doubles. Fixed the problem by checking for string columns and reading/writing them as strings. Note that strings can have a maximum length of 256 characters. Fix is v4.73.


Keywords: HEAsoft, extractor

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

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

Preprints

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.

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

Preprints

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.

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

Preprints

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.

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

Preprints

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.