http://adsabs.harvard.edu/abs/2012Icar..217..474M

The 1.02 μm wavelength thermal emission of the nightside of Venus is strongly anti-correlated to the elevation of the surface. The VIRTIS instrument on Venus Express has mapped this emission and therefore gives evidence for the orientation of Venus between 2006 and 2008. The Magellan mission provided a global altimetry data set recorded between 1990 and 1992. Comparison of these two data sets reveals a deviation in longitude indicating that the rotation of the planet is not fully described by the orientation model recommended by the IAU. This deviation is sufficiently large to affect estimates of surface emissivity from infrared imaging. A revised period of rotation of Venus of 243.023 ± 0.002 d aligns the two data sets. This period of rotation agrees with pre-Magellan estimates but is significantly different from the commonly accepted value of 243.0185 ± 0.0001 d estimated from Magellan radar images. It is possible that this discrepancy stems from a length of day variation with the value of 243.023 ± 0.002 d representing the average of the rotation period over 16 years.

http://arxiv.org/abs/1202.3388

by

Sachiko Kuroyanagi, Koichi Miyamoto, Toyokazu Sekiguchi, Keitaro Takahashi, Joseph Silk

http://xxx.lanl.gov/abs/1202.1167

http://arxiv.org/abs/1202.0892

Philippe Brax

http://arxiv.org/pdf/1202.0740v1.pdf

Roberto Gobbetti, Matthew Kleban
http://arxiv.org/pdf/1201.6380v1.pdf

http://arxiv.org/abs/1201.5732

http://arxiv.org/abs/1201.5961

http://arxiv.org/abs/1201.5926

Authors: Ana Achucarro, Jinn-Ouk Gong, Sjoerd Hardeman, Gonzalo A. Palma, Subodh P. Patil

http://arxiv.org/abs/1201.6342

Authors: Stephan J.G. Gift
Ether drift resulting from the rotation of the Earth has been detected. This was accomplished using GPS technology in a modified Michelson-Morley experiment. The original Michelson-Morley experiment searched for ether drift by observing round-trip light travel time differences using interference fringe shifts. This method is limited by length contraction effects that significantly reduce any fringe shifts. In the modified approach elapsed time for one-way light transmission is directly determined using GPS clocks. The method yields travel time differences for light transmission in the East-West direction but not in the North-South direction consistent with rotationally-induced ether drift.
Comments: 12 Pages. Accepted for publication in Applied Physics Research

http://vixra.org/abs/1201.0058

Can gravity distinguish between Dirac and Majorana Neutrinos?

Satellites around massive galaxies since z~2

Accretion of minor satellites has been postulated as the most likely mechanism to explain the significant size evolution of the massive galaxies over cosmic time. Using a sample of 629 massive (Mstar~10^11 Msun) galaxies from the near-infrared Palomar/DEEP-2 survey, we explore which fraction of these objects has satellites with 0.01 Msat < Mcentral < 1 (1:100) up to z=1 and which fraction has satellites with 0.1 Msat < Mcentral < 1 (1:10) up to z=2 within a projected radial distance of 100 kpc. We find that the fraction of massive galaxies with satellites, after the background correction, remains basically constant and close to ~30% for satellites with a mass ratio down to 1:100 up to z=1, and ~15% for satellites with a 1:10 mass ratio up to z=2. The family of spheroid-like massive galaxies presents a 2-3 times larger fraction of objects with satellites than the group of disk-like massive galaxies. A crude estimation of the number of 1:3 mergers a massive spheroid-like galaxy experiences since z~2 is around 2. For a disk-like galaxy this number decreases to ~1.

http://www.scirp.org/journal/PaperInformation.aspx?paperID=16372

It is shown that in order that the fluid pressure and acceleration are uniform and finite in Einstein’s Static
Universe (ESU),  , the cosmological constant, is zero.  being a fundamental constant, should be the
same everywhere including the Friedman model. Independent proofs show that it must be so. Accordingly,
the supposed acceleration of the universe and the attendant concept of a “Dark Energy” (DE) could be an
illusion; an artifact of explaining cosmological observations in terms of an oversimplified model which is
fundamentally inappropriate. Indeed observations show that the actual universe is lumpy and inhomogeneous
at the largest scales. Further in order that there is no preferred centre, such an inhomogeneity might be ex-
pressed in terms of infinite hierarchial fractals. Also, the recent finding that the Friedman model intrinsically
corresponds to zero pressure (and hence zero temperature) in accordance with the fact that an ideal Hubble
flow implies no collision, no randomness (Mitra, Astrophys. Sp. Sc., 333,351, 2011) too shows that the
Friedman model cannot represent the real universe having pressure, temperature and radiation. Dark Energy
might also be an artifact of the neglect of dust absorption of distant Type 1a supernovae coupled with likely
evolution of supernovae luminosities or imprecise calibration of cosmic distance ladders or other systemetic
errors (White, Rep. Prog. Phys., 70, 883, 2007). In reality, observations may not rule out an inhomogeneous
static universe (Ellis, Gen. Rel. Grav. 9, 87, 1978), if the fundamental “constants” are indeed constant.

http://arxiv.org/abs/1112.4821

The motion of a charged particle is influenced by the self-force arising from the particle’s interaction with its own field. In a curved spacetime, this self-force depends on the entire past history of the particle and is difficult to evaluate. As a result, all existing self-force evaluations in curved spacetime are for particles moving along a fixed trajectory. Here, for the first time, we overcome this longstanding limitation and present fully self-consistent orbits and waveforms of a scalar charged particle around a Schwarzschild black hole.

Including the effects of electric currents in any description of the origin, shape, or motion of cosmic magnetized plasma is crucial for understanding many observed astronomical phenomena. The Maxwell (Heaviside) equations are based on real experimental measurements. These fundamental expressions clearly link electric current densities, magnetic flux densities, and electric fields into a unified conceptual whole. Examples are presented to demonstrate the pitfalls of omitting the contribution and effects of currents from descriptions of the behavior of magnetic fields. An example suggests a possible electrical explanation of the enigmatic cyclical reversal of magnetic polarities near sunspots and demonstrates the unique insight afforded by including the causal effects of currents.

http://www.benthamscience.com/open/toaaj/openaccess2.htm

http://www.nytimes.com/2011/12/14/science/tantalizing-hints-but-no-direct-proof-in-search-for-higgs-boson.html

http://arxiv.org/pdf/1112.1435

A proof of the Riemann Hypothesis:

http://arxiv.org/abs/1110.2952

The Riemann Hypothesis is Unprovable:

http://arxiv.org/abs/math/0309367v4

http://astrojournalclub.wordpress.com/2011/11/27/this-weeks-meeting-mentoring-for-young-scientists/

Come discuss!

http://arxiv.org/abs/1111.5378

Alexandre Le Tiec, Luc Blanchet, Bernard F. Whiting

First laws of black hole mechanics, or thermodynamics, come in a variety of different forms. In this paper, from a purely post-Newtonian (PN) analysis, we obtain a first law for binary systems of point masses moving along an exactly circular orbit. Our calculation is valid through 3PN order and includes, in addition, the contributions of logarithmic terms at 4PN and 5PN orders. This first law of binary point-particle mechanics is then derived from first principles in general relativity, and analogies are drawn with the single and binary black hole cases. Some consequences of the first law are explored for PN spacetimes. As one such consequence, a simple relation between the PN binding energy of the binary system and Detweiler’s redshift observable is established. Through it, we are able to determine with high precision the numerical values of some previously unknown high order PN coefficients in the circular-orbit binding energy. Finally, we propose new gauge invariant notions for the energy and angular momentum of a particle in a binary system.

Quantum states are the key mathematical objects in quantum theory. It is therefore surprising that physicists have been unable to agree on what a quantum state represents. There are at least two opposing schools of thought, each almost as old as quantum theory itself. One is that a pure state is a physical property of system, much like position and momentum in classical mechanics. Another is that even a pure state has only a statistical significance, akin to a probability distribution in statistical mechanics. Here we show that, given only very mild assumptions, the statistical interpretation of the quantum state is inconsistent with the predictions of quantum theory. This result holds even in the presence of small amounts of experimental noise, and is therefore amenable to experimental test using present or near-future technology. If the predictions of quantum theory are confirmed, such a test would show that distinct quantum states must correspond to physically distinct states of reality.

http://xxx.lanl.gov/abs/1111.3328v1

Jonathan Gair,1 Nicola ́s Yunes,2, 3 and Carl M. Bender4

http://arxiv.org/pdf/1111.3605v1

An expected source of gravitational waves for future detectors in space are the inspirals of small compact objects into much more massive black holes. . On short timescales the orbit of the small object is approximately geodesic. Over the course of an inspiral, a typical system will pass through resonances where two of these frequencies become commensurate. The effect of the resonance will be to alter significantly the rate of inspiral for the duration of the resonance.

An update on OPERA’s observation of superluminal neutrinos has been posted on the hep-ex arxiv: http://arxiv.org/abs/1109.4897

See some discussion on this here.

This paper did not appear on astro-ph, nonetheless i’d like to discuss it.

It is about the perception of astrology and other unscientific views.

http://adsabs.harvard.edu/abs/2011AEdRv..10a0101S

Paul Hartogh, Dariusz C. Lis, Dominique Bockelée-Morvan, Miguel de Val-Borro, Nicolas Biver, Michael Küppers, Martin Emprechtinger, Edwin A. Bergin, Jacques Crovisier, Miriam Rengel, Raphael Moreno, Slawomira Szutowicz & Geoffrey A. Blake

Herschel discovery on the D/H ratio in water molecules in comet Hartley 2.

Awarded to Saul Perlmutter, Brian P. Schmidt, and Adam G. Riess.

http://www.nobelprize.org/nobel_prizes/physics/laureates/2011/index.html

The OPERA Collaboraton: T. Adam, N. Agafonova, A. Aleksandrov, O. Altinok, P. Alvarez Sanchez, S. Aoki, A. Ariga, T. Ariga, D. Autiero, A. Badertscher, A. Ben Dhahbi, A. Bertolin, C. Bozza, T. Brugiére, F. Brunet, G. Brunetti, S. Buontempo, F. Cavanna, A. Cazes, L. Chaussard, M. Chernyavskiy, V. Chiarella, A. Chukanov, G. Colosimo, M. Crespi, N. D’Ambrosios, Y. Déclais, P. del Amo Sanchez, G. De Lellis, M. De Serio, F. Di Capua, F. Cavanna, A. Di Crescenzo, D. Di Ferdinando, N. Di Marco, S. Dmitrievsky, M. Dracos, D. Duchesneau, S. Dusini, J. Ebert, I. Eftimiopolous, O. Egorov, A. Ereditato, L.S. Esposito, J. Favier, T. Ferber, R.A. Fini, T. Fukuda, A. Garfagnini, G. Giacomelli, C. Girerd, M. Giorgini, M. Giovannozzi, J. Goldberga, C. Göllnitz, L. Goncharova, Y. Gornushkin, et al. (117 additional authors not shown)

(Submitted on 22 Sep 2011)

The OPERA neutrino experiment at the underground Gran Sasso Laboratory has measured the velocity of neutrinos from the CERN CNGS beam over a baseline of about 730 km with much higher accuracy than previous studies conducted with accelerator neutrinos. The measurement is based on high-statistics data taken by OPERA in the years 2009, 2010 and 2011. Dedicated upgrades of the CNGS timing system and of the OPERA detector, as well as a high precision geodesy campaign for the measurement of the neutrino baseline, allowed reaching comparable systematic and statistical accuracies. An early arrival time of CNGS muon neutrinos with respect to the one computed assuming the speed of light in vacuum of (60.7 \pm 6.9 (stat.) \pm 7.4 (sys.)) ns was measured. This anomaly corresponds to a relative difference of the muon neutrino velocity with respect to the speed of light (v-c)/c = (2.48 \pm 0.28 (stat.) \pm 0.30 (sys.)) \times 10-5.

http://arxiv.org/abs/1109.0081

Nichols and Chen, Caltech

We adapt a method of matching post-Newtonian and black-hole-perturbation theories on a timelike surface (which proved useful for understanding head-on black-hole-binary collisions) to treat equal-mass, inspiralling black-hole binaries. We first introduce a radiation-reaction potential into this method, and we show that it leads to a self-consistent set of equations that describe the simultaneous evolution of the waveform and of the timelike matching surface. This allows us to produce a full inspiral-merger-ringdown waveform of the l=2, m=2,-2 modes of the gravitational waveform of an equal-mass black-hole-binary inspiral. These modes match those of numerical-relativity simulations well in phase, though less well in amplitude for the inspiral. As a second application of this method, we study a merger of black holes with spins antialigned in the orbital plane (the “superkick” configuration). During the ringdown of the superkick, the phases of the mass- and current-quadrupole radiation become locked together, because they evolve at the same quasinormal mode frequencies. We argue that this locking begins during merger, and we show that if the spins of the black holes evolve via geodetic precession in the perturbed black-hole spacetime of our model, then the spins precess at the orbital frequency during merger. In turn, this gives rise to the correct behavior of the radiation, and produces a kick similar to that observed in numerical simulations.

http://www.nature.com/nature/journal/v477/n7362/full/nature10377.html

And for commentary:

http://www.nature.com/nature/journal/v477/n7362/full/477037a.html

ATel #3581: Young Type Ia Supernova PTF11kly in M101

http://arxiv.org/pdf/1107.0766v1

The motion of a small compact (SCO) object in a background spacetime is investigated further in the context of a class of model nonlinear scalar field theories that have a perturbative structure analogous to the General Relativistic description of extreme mass ratio inspirals (EMRIs). We derive regular expressions for the scalar perturbations generated by the motion of the compact object that are valid through third order in ε, the size of the SCO to the background curvature length scale. Our results for the field perturbations are compared to those calculated through second order in ε by Rosenthal in [1] and found to agree. However, our procedure for regularizing the scalar perturbations is considerably simpler. Following the Detweiler-Whiting scheme, we use our results for the regular expressions for the field and derive the regular self-force corrections through third order. We find agreement with our previous derivation based on a variational principle of an effective action for the worldline associated with the SCO thereby demonstrating the internal consistency of our formalism. This also explicitly demonstrates that the Detweiler-Whiting decomposition of Green’s functions is a valid and practical method of self force computation at higher orders in perturbation theory and, more generally, at all orders in perturbation theory, as we show in an appendix. Finally, we identify a central quantity, which we call a master source, from which all other physically relevant quantities are derivable. Specifically, knowing the master source through some order in ε allows one to construct the waveform measured by an observer, the regular part of the field and its derivative on the worldline, the regular part of the self force, and various orbital quantities such as shifts of the innermost stable circular orbit, etc., when restricting to conservative dynamics. The existence of a master source together with the regularization methods implemented in this series should be indispensable for derivations of higher-order gravitational self force corrections in the future.

1105.3069

http://lanl.arxiv.org/abs/1105.3069v1

The stability properties of relativistic stars against gravitational collapse to black hole is a classical problem in general relativity. A sufficient criterion for secular instability was established by Friedman, Ipser and Sorkin (1988), who proved that a sequence of uniformly rotating barotropic stars is secularly unstable on one side of a turning point and then argued that a stronger result should hold: that the sequence should be stable on the opposite side, with the turning point marking the onset of secular instability. We show here that this expectation is not met. By computing in full general relativity the $F$-mode frequency for a large number of rotating stars, we show that the neutral-stability point, i.e., where the frequency becomes zero, differs from the turning point for rotating stars. Using numerical simulations we validate that the new criterion can be used to assess the dynamical stability of relativistic rotating stars.

A. P. Jones and J. A. Nuth III

(PDF)

Context. There is a long-standing conundrum in interstellar dust studies relating to the discrepancy between the time-scales for dust
formation from evolved stars and the apparently more rapid destruction in supernova-generated shock waves.
Aims. We re-examine some of the key issues relating to dust evolution and processing in the interstellar medium.
Methods. We use recent and new constraints from observations, experiments, modelling and theory to re-evaluate dust formation in
the interstellar medium (ISM).
Results. We find that the discrepancy between the dust formation and destruction time-scales may not be as significant as has previ-
ously been assumed because of the very large uncertainties involved.
Conclusions. The derived silicate dust lifetime could be compatible with its injection time-scale, given the inherent uncertainties in
the dust lifetime calculation. The apparent need to re-form significant quantities of silicate dust in the tenuous interstellar medium
may therefore not be a strong requirement. Carbonaceous matter, on the other hand, appears to be rapidly recycled in the ISM and,
in contrast to silicates, there are viable mechanisms for its re-formation in the ISM.

This week’s issue of Nature has a special on the future of the PhD. In a series of articles the academic pyramid (Ph.D. student/post-doc/permanent staff) is being discussed, in particular the perceived overproduction of PhDs, induced by funding systems around the world. The editorial provides a good summary of various viewpoints: http://www.nature.com/nature/journal/v472/n7343/full/472259b.html

http://scienceblogs.com/catdynamics/2011/04/nasa_wiping_the_slate_clean.php

IXO and LISA are dead and disbanded as NASA missions.
We are looking at a very thin pipeline and few new missions for a while, unless there is drastic new direction from above and strong guidance on funding.

F. Francisco, O. Bertolami, P. J. S. Gil, J. Páramos

(Submitted on 27 Mar 2011)

Comments: 11 pages, 7 figures, 3 tables

Subjects: Space Physics (physics.space-ph); Instrumentation and Methods for Astrophysics (astro-ph.IM); General Relativity and Quantum Cosmology (gr-qc)

arXiv:1103.5222v1

We present an improved method to compute the radiative momentum transfer in the Pioneer 10 & 11 spacecraft that takes into account both diffusive and specular reflection. The method allows for more reliable results regarding the thermal acceleration of the deep-space probes, confirming previous findings. A parametric analysis is performed in order to set an upper and lower-bound for the thermal acceleration and its evolution with time.

http://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys1907.html

http://arxiv.org/pdf/1101.2451v2

We show by explicit construction that for every solution of the incompressible Navier-Stokes equation in $p+1$ dimensions, there is a uniquely associated “dual” solution of the vacuum Einstein equations in $p+2$ dimensions. The dual geometry has an intrinsically flat timelike boundary segment $\Sigma_c$ whose extrinsic curvature is given by the stress tensor of the Navier-Stokes fluid. We consider a “near-horizon” limit in which $\Sigma_c$ becomes highly accelerated. The near-horizon expansion in gravity is shown to be mathematically equivalent to the hydrodynamic expansion in fluid dynamics, and the Einstein equation reduces to the incompressible Navier-Stokes equation. For $p=2$, we show that the full dual geometry is algebraically special Petrov type II. The construction is a mathematically precise realization of suggestions of a holographic duality relating fluids and horizons which began with the membrane paradigm in the 70’s and resurfaced recently in studies of the AdS/CFT correspondence.

http://www.nature.com/nature/journal/v469/n7331/full/nature09717.html

Searches for very-high-redshift galaxies over the past decade have yielded a large sample of more than 6,000 galaxies existing just 900–2,000 million years (Myr) after the Big Bang (redshifts 6 > z > 3; ref. 1). The Hubble Ultra Deep Field (HUDF09) data have yielded the first reliable detections of z ≈ 8 galaxies that, together with reports of a γ-ray burst at z ≈ 8.2 (refs 10, 11), constitute the earliest objects reliably reported to date. Observations of z ≈ 7–8 galaxies suggest substantial star formation at z > 9–10 (refs 12, 13). Here we use the full two-year HUDF09 data to conduct an ultra-deep search for z ≈ 10 galaxies in the heart of the reionization epoch, only 500 Myr after the Big Bang. Not only do we find one possible z ≈ 10 galaxy candidate, but we show that, regardless of source detections, the star formation rate density is much smaller (~10%) at this time than it is just ~200 Myr later at z ≈ 8. This demonstrates how rapid galaxy build-up was at z ≈ 10, as galaxies increased in both luminosity density and volume density from z ≈ 10 to z ≈ 8. The 100–200 Myr before z ≈ 10 is clearly a crucial phase in the assembly of the earliest galaxies.

http://xxx.lanl.gov/abs/1101.3765

We introduce a reduced basis approach as a new paradigm for modeling, representing and searching for gravitational waves. We construct waveform catalogs for non-spinning compact binary coalescences, and we find that for accuracies of $99\%$ and $99.999\%$ the method generates a factor of about $10-10^5$ fewer templates than standard placement methods. The continuum of gravitational waves can be represented by a finite and comparatively compact basis. The method is robust under variations in the noise of detectors, implying that only a single catalog needs to be generated.

http://www.nature.com/nature/journal/v468/n7325/full/nature09601.html

http://arxiv.org/abs/1012.5622

http://arxiv.org/abs/1012.5172

For some reason this has not appeared normally.

http://xxx.lanl.gov/abs/1011.6142

Dany Page (1), Madappa Prakash (2), James M. Lattimer (3), Andrew W. Steiner (4)

We propose that the recently observed cooling of the neutron star in Cassiopeia A is due to enhanced neutrino emission from the onset of the breaking and formation of neutron Cooper pairs in the 3P2 channel. To account for the observed cooling rate, which is significantly faster than that expected from the modified Urca process, the critical temperature for this superfluid transition is required to be ~ 0.5×10^9 K. Our prediction that this cooling will continue for several decades at an almost constant rate can be tested by continuous monitoring of this neutron star.

Special introductions of new postdocs and their research. Come ready for wipeboard action.
10:45am, CfAO atrium

In next week’s discussion group (2010-11-30), we’ll spend a few minutes hearing about

• http://www.nature.com/nature/journal/v468/n7320/full/nature09506.html

Quantum electrodynamics describes the interactions of electrons and photons. Electric charge (the gauge coupling constant) is energy dependent, and there is a previous claim that charge is affected by gravity (described by general relativity) with the implication that the charge is reduced at high energies. However, that claim has been very controversial and the matter has not been settled. Here I report an analysis (free from the earlier controversies) demonstrating that quantum gravity corrections to quantum electrodynamics have a quadratic energy dependence that result in the electric charge vanishing at high energies, a result known as asymptotic freedom.

Johny Setiawan1,∗, Rainer J. Klement1, Thomas Henning1, Hans-Walter Rix1 , Boyke Rochau1, Jens Rodmann2 and Tim Schulze-Hartung1

1Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany.
2European Space Agency, Space Environment and Effects Section, ESTEC, Keplerlaan 1, 2201 AZ Noordwijk, Netherlands.

Stars in their late stage of evolution, such as Horizontal Branch stars, are still largely unexplored for planets. We report the detection of a planetary companion around HIP 13044, a very metal-poor star on the red Horizontal Branch, based on radial velocity observations with a high-resolution spectrograph at the 2.2-m MPG/ESO telescope. The star’s periodic radial velocity variation of P = 16.2 days caused by the planet can be distinguished from the periods of the stellar activity indicators. The minimum mass of the planet is 1.25 Mjup and its orbital semimajor axis 0.116 AU. Because HIP 13044 belongs to a group of stars that have been accreted from a disrupted satellite galaxy of the Milky Way, the planet most likely has an extragalactic origin.

Abstract
PDF

Not on arXiv (yet?):

http://iopscience.iop.org/0004-637X/724/2/1402/

The study of cold atomic hydrogen (H I) in molecular clouds has the potential to significantly improve our understanding of the formation of molecular clouds, the atomic to molecular hydrogen conversion process, and star formation. Results from the first large survey of H I Narrow Self Absorption (HINSA) features outside of the Taurus Molecular Cloud Complex are presented. Previous hypotheses that cold atomic hydrogen represents the third largest constituent of molecular clouds are confirmed with a mean abundance of 10^–2.8 in comparison with the total proton column density. HINSA features are observed in over 80% of the observed clouds, accompanied by indications that cold H I probably exists in all clouds. We find that HINSA features are observable to distances of at least 700 pc. Nine clouds have been mapped in detail revealing that HINSA abundances can vary significantly within a cloud both spatially and in an individual velocity component. Possible explanations for this phenomenon are briefly discussed.

P. B. Demorestp, T. Pennucc, S. M. Ransom, M. S. E. Roberts, & J. W. T. Hessels

Journal name:

Nature  467  1081–1083 (28 October 2010)

Neutron stars are composed of the densest form of matter known to exist in our Universe, the composition and properties of which are still theoretically uncertain. Measurements of the masses or radii of these objects can strongly constrain the neutron star matter equation of state and rule out theoretical models of their composition^{1, 2}. The observed range of neutron star masses, however, has hitherto been too narrow to rule out many predictions of ‘exotic’ non-nucleonic components^{3, 4, 5, 6}. The Shapiro delay is a general-relativistic increase in light travel time through the curved space-time near a massive body⁷. For highly inclined (nearly edge-on) binary millisecond radio pulsar systems, this effect allows us to infer the masses of both the neutron star and its binary companion to high precision^{8, 9}. Here we present radio timing observations of the binary millisecond pulsar J1614-2230^{10, 11} that show a strong Shapiro delay signature. We calculate the pulsar mass to be (1.97 ± 0.04)M_⊙, which rules out almost all currently proposed^{2, 3, 4, 5} hyperon or boson condensate equations of state (M_⊙, solar mass). Quark matter can support a star this massive only if the quarks are strongly interacting and are therefore not ‘free’ quarks¹².

Cenko et al. 2010 published:

The Collimation and Energetics of the Brightest Swift Gamma-ray Bursts

A paper I missed at the time on astro-ph.

They get E_gamma for a few bright GRBs, and claim a clear jet break for them, and then infer an E_gamma for each that is higher than the early Frail and Bloom results. None of the breaks seem very compelling to me; e.g. GRB050904, where they claim an X-ray and optical break in Tagliaferri et al. (2005), where the X-rays are totally flare-dominated, and Tagliaferri says nothing about the X-rays.

Is this type of collimation work meaningless?

An analysis of over 50,000 Science papers suggests that it could pay to include more references:

http://www.nature.com/news/2010/100813/full/news.2010.406.html

http://www.strudel.org.uk/blog/astro/images//20100719_astronomer_HR_diagram.png

Press release:
http://hubblesite.org/newscenter/archive/releases/2010/17/

Science paper:
http://hubblesite.org/pubinfo/pdf/2010/17/pdf.pdf

This paper is notable because it presents the first exo-planetary system where the inclination between the orbits of two different planets has been determined (30 degrees).

Some pretty cool movies and pictures from this new spacecraft:

http://science.nasa.gov/science-news/science-at-nasa/2010/21apr_firstlight/

Astro-ph will not have any new postings today due to maintenance on the arXiv website. UPDATE: Astro-ph did in fact update tonight, but at a bizarre time (after 10pm PST). The new listings are now posted.

The maintenance overhauls the submission system on arXiv, and has resulted in a change in how post order on astro-ph is determined:

Submissions are assigned identifiers and appear in the listings in order based on the submission time (the last time the “Submit” button was selected at the end of the submission process). An edit and subsequent “Submit” will reset this time and thus change position in the listings. Edits are permitted between 16:00 and the 20:00 announcement time (EST). However, doing this will remove the submission from that day’s announcements and delay it until the next day.

In other words, (I think) your article has to correctly parse when you first submit it in order to appear at the top of the list. Additionally, posts are forced to appear the next day if there are any edits after 1pm PST. I do not know if these posts automatically appear at the top of the next day’s listing.

More info on the new submission process is available here.

A population of extrasolar planets has been uncovered with minimum masses of 1.9–10 times the Earth’s mass, called super-Earths, but atmospheric studies can be precluded by the distance and size of their stars. Here, observations of the transiting planet GJ 1214b are reported; it has a mass 6.55 times that of the Earth and a radius 2.68 times the Earth’s radius. The star is small and only 13 parsecs away, permitting the study of the planetary atmosphere with current observatories.

http://www.nature.com/nature/journal/v462/n7275/pdf/nature08679.pdf

Also known as “How do you organize your pdfs and other electronic data?”

Has JafRef changed your life, or maybe it’s BibDesk?  Anyone out there think it’s worth to shell out for Papers?  Do you use online services like Bibsonomy?  Are all your pdfs marked up with Skim?  Come share your favorite tips to get the masses of papers organized!

http://www.nasa.gov/mission_pages/LCROSS/main/prelim_water_results.html