Preprints

Roelofs et al. derive parallaxes for a set of AM CVn binaries and predict LISA GW signals.

Dietrich et al. describe BLOX, a program to select galaxy clusters based on optical, X-ray and weak lensing shear.

Percival et al. measure the baryon oscillation signal at z=0.2 and z=0.35 using SDSS and 2dFGRS to constrain w=-1.004 +/- 0.089 for a flat model including the supernova and CMB constraints.

Wallin et al. place limits on deviations from Newtonian gravity in the outer Solar System through observations of the orbits of TNOs.

Markevitch points out that X-ray emission from clusters of galaxies depends on the He abundance in their cores which is unknown (and may be enhanced due to sedimentation). Combining SZ measurements with distances determined using other techniques can be used to estimate the He abundance.

Ruiter et al. calculate the LISA foreground due to mass-transferring binaries and find that it becomes significant at frequencies above ~7 mHz.

Bickel et al. develop methods for searching for periodicity in photon event times with application in the gamma-ray regime.

Prix & Whelan apply F-statistic methods developed for LIGO to the MLDC binary challenges.

srcut and sresc seg fault in xspec v12

Heather Matheson at U.Manitoba reported that srcut seg faults in v12. This turned out to be due to an error in the C++ to Fortran conversion for the power-law routine that is called by srcut and sresc.

another seg fault in compps

I had a slight error in the dynamic memory allocation for the compps model which caused a potential seg fault if the response had < 88 energy bins. This is patched in both v11 and v12.

Preprints

Jee et al. use weak-lensing analysis of Cl0024+17 and find a ring of dark matter which they interpret as the result of a high-velocity line-of-sight collision.

Tsalmantza et al. present the first results from a program to generate a library of synthetic galaxy spectra to be used to classify the several million unresolved galaxies whose spectra will be acquired by Gaia.

Wu & Wang calculate Fe K line shapes from relativistic accreting disks including the effects of self-shadowing.

Tornatore et al. use hydro simulations to investigate chemical evolution in clusters of galaxies.

Trimble et al. summarize astrophysics in 2006.

Padmanabhan reviews dark energy cosmology, argues that only a cosmological constant makes sense and that the problem cannot be satisfactorily solved at our current level of (mis)understanding.

Fiore et al. combine optical, IR, and X-ray observations of the Chandra Deep Field South to identify the Compton-thick AGN that have so far been missing from deep Chandra observations.

Kelly describes a Bayesian approach using Gaussian mixtures for linear regression in the presence of measurement errors, non-detections, and selection effects.

Eckert et al. analyze a 1.1Ms Integral ISGRI observation of the Coma cluster to find an extended hard X-ray excess in the direction of the infalling cluster A1376.

Sanders & Fabian continue their analysis of the very deep Chandra observation of the Perseus cluster finding a) the ripples interpreted as sound waves carry a significant fraction of the energy lost to radiative cooling b) the distribution of metals peaks at 40 kpc and is clumpy on scales of 5 kpc c) there is no evidence for thermal emission from the radio bubbles.

Repin et al. give analytic approximations for the relativistic Fe K line shape from accretion disks. A table is available.

gsmooth

Jeremy Sanders provides a faster version of the gsmooth model which precalculates an array of erf values then interpolates on them.

Preprints

Stanek proposes a an alternative history version of astro-ph for failed telescope and other proposals. Probably should have come out on Apr 1.

Feroz & Hobson describe an efficient sampling method for multimodel and/or degenerate distributions when calculating Bayesian evidence.

Hallman et al. use numerical simulations to show that using beta-model fits to X-ray data in the analysis of SZE observations leads to systematic biases and suggest a simple correction.

Miller reviews relativistic X-ray lines from the inner regions of accretion disks.

Magliocchetti & Bruggen combine X-ray data from the REFLEX and NORAS samples and radio data from the NVSS to investigate the effects of radio sources on the cluster L_X-T relation.

Kitaura & Ensslin survey Bayesian reconstruction schemes for large-scale structure.

Kerkyacharian et al. present a new estimation method for the inverse problem building on SVD decomposition.

building with gfortran

Successfully built headas on my Mac using the gfortran from the installer supplied at gcc.gnu.org. This places the gfortran library files in /usr/local/gfortran/lib so configure has to be altered so that F77LIBS4C in hmakerc includes this directory. If the gfortran plug-in for Xcode is used then the gfortran library files end up in /usr/local/lib which is in the link path anyway so need not be specified in F77LIBS4C. Also had to update cctools to avoid an undefined dso_handle. Had to add DHAVE_ETIME=1 to DEFS in hmakerc to ensure that etime is not defined again in xanlib/sysdep/sysc.c.

Not directly connected to gfortran but we discovered cod.dhf was not being built - this requires running hlpdhf on cod.hlp which means ensuring ia/doc is built ahead of qdp.

udmget : Too many blocks error

Both Roderick Johnstone and Ewan O'Sullivan have reported getting "Too many blocks" errors when using xspec v11 with complicated models. MAXBLK is set to 100 in udmget.c and there is no good reason why this should be so small. I've changed this to 1000 for the next release which should solve these problems.

Note that Bryan has updated xspec/src/tcl/Makefile so that it will rebuild libxantcl* when changes are made in the libxanlib* library. I really should be building libxantcl under the xanlib tree rather than the somewhat bizarre way it is done at present under the xspec tree.

hk file extension numbers in xselect

Change requested by Suzaku XIS team to allow multiple extensions in HK files. The read hk command now allows an extension to be given eg filename+3. This entire name plus extension is passed to maketime when doing a select hk. The code change does in principle allow the same syntax to be used when reading an event file however this is disabled because in some places xselect appends a +1 extension descriptor to the event file name.

xspec v11 and gfortran block data problem

Put in workarounds for the block data initialization problem with gfortran. None of these should have any discernible effect but we shall see. The changes were in the default values for genfit, the default names for model components, the default gain parameters in response, and the atdata.f routine used by the NEI models.

This latter has been changed in xspec v12 as well.

Errors on fluxes of model components

A frequently requested enhancement for xspec is to be able to estimate the error on the flux from part of the model eg the model without Galactic absorption. I've now written a more detailed explanation and provided a helpful Tcl script. It should be possible to incorporate this functionality within xspec itself.

gfortran compiler and BLOCK DATA

The gfortran compiler appears to have a known issue with intializing common variables in a BLOCK DATA. This leads to problems in xparse with the XPRSBD block and causes msetup to fail. The workaround is to create a dummy routine which calls XPRSBD and insert a call in any xparse routine that uses variables in the BLOCK DATA. This fixes the problem and xspec v11 builds and runs the session/xspec.xcm script successfully. However, there are other BLOCK DATA in HEAsoft so we need to make similar fixes for them. Note that in Fortran 90 and later code BLOCK DATA is supposed to be replaced by MODULE.

xspec background models

I wrote a slightly longer explanation of the v12 replacement for v11 /b models. I also added a link from the xspec FAQ.

Preprints

Evans et al. describe the on-line database of Swift GRB lightcurves.

Tombesi et al. find a variable redshifted Fe K line with a modulation timescale of 27 ksec using XMM observations of NGC3783.

Bonavita & Desidera note from a literature search that there appears to be no difference between planet detection rates in single and binary star systems.

Migliori et al. analyze XMM observations of the radio lobes of Pictor A and finds that the particle energy is above the equipartition value and that spacial changes in radio flux are due to magnetic field variation.

Zhang et al. discuss how to test standard gravity on cosmological scales by comparing matter overdensity to gravitational lensing.

Kurucz argues that the exoplanets detected so far are "cryptoplanets" formed from matter ejected by protostars.

Bryan et al. (the CMU astrostatisticians) present a new method to determine multidimensional confidence intervals and apply it to the cosmological data.

Porter & Ferland discuss the addition of He I like lines to Cloudy and their use for diagnostics.

Afshordi considers the accuracy of mass estimates from SZ surveys of clusters.

Erickcek et al. note that the X-ray quantum calorimeter (XQC) rocket flight can be used to place strong constraints on interaction cross-sections between baryons and dark matter.

Rudnick et al. point out that the WMAP cold-spot corresponds to a dip in the number counts of NVSS sources. If this is Sachs-Wolfe effect it would require a void of radius 140 Mpc.

Werner et al. analyze XMM and Suzaku observations of Sersic 159-03 and find a central soft excess but no evidence for lines ruling out thermal sources.

long hk and mkf selection expressions in xselect

The Suzaku XIS team ran into a problem with a really long hk selection expression in xselect. I've increased the relevant strings to 4098 characters which should be enough for the moment.

swind1 fix

The swind1.f source file available on the extra models page had an error reported by Roderick Johnstone - lenact was not declared. Fixed this.

gfortran and mac

Just for future reference here is the link for the gfortran plug-in to Xcode.

hardcopy in xspec v12

The hardcopy command is implemented through a script hardcopy.tcl in Xspec/src/scripts. This script had an error and didn't work. Note that implementing a command through a script means that abbreviating the command doesn't work.

uninitialized string in xinfix

Glenn Morris reported bizarre behaviour in xspec11 when giving setplot an invalid argument. This turned out to be an uninitialized string in xanlib/xparse/xinfix.f which has somehow avoided detection before now. Note that we really need to fix the Makefile in xspec11/src/tcl so that libxantcl*.a is rebuilt if libxanlib*.a is changed.

compps model

Hiromitsu Takahashi reports that the compps model in xspec seg faults when using the Suzaku XIS response. This is because there were hard-wired array sizes in xscompps.f. I replaced these by dynamic arrays using the standard method as well as removing some unused variables. This change in is v11.3.2ae and will be in v12 shortly.