Day 531

Friday.


1310.4208
Kepler-like Multi-plexing for mass production of microlens parallaxes
Gould, Horne

A Kepler-like wide-field satellite in Solar orbit can get microlens parallaxes for several thousands events per year.  Such a satellite would also: roughly double the number of planet detections (and mass/distance determinations); yield a trove of brown-dwarf binaries with masses, distances and (frequently) full orbits, enable new probes of the stellar mass function, identify isolated BH candidates, and more.  The degraded Kepler satellite can demonstrate these capabilities and make substantial initial inroads into the science potential.  Differences to the current Kepler to optimize microlens parallax capabilities would mostly reduce costs.  The wide-angle approach advocated has only recenetly become superior to the old narrow-angle approach.


1310.4278
Horizon Run 3: topology as a standard ruler
Speare, Gott, Kim, Park

Estimate the accuracy in determination of the cosmological distance scale measured by topology analysis, using physically self bound cold dark matter halo distribution (associated with massive galaxies in the simulation---mock catalog similar to BOSS survey).  1.7% fractional uncertainty in angular diameter distance to z=0.6; improvement over former calibrations, and a competitive error estimate with next BAO scale techniques.

1310.4317
Probing AGN triggering mechanisms through the starburstiness of the host galaxies
Lamastra et al

Estimate the fraction of AGNs hosted by SB galaxies, as a function of AGN luminosity, assuming AGN and starburst triggered by galaxy interactions during merging.  SAM AGN and SB, based on on MCMC merging trees.  The predicted f_bursty increases steeply with AGN luminosity from <0.2 at L_X<1e44 ergs/ to >0.9 at L_X>1e45 erg/s over 0<z<6.  Compare model with AGNs in XMM-COSMOS field at 0.3<z<2, and for QSOs in 2<z<6.5.  Find preliminary indications that under conservative assumptions, half of the QSO hosts are starburst galaxies.  

1310.4498
Identification of a Jet-driven supernova remnant in the small Magellanic cloud: evidence for the enhancement of bipolar explosions at low metallicity
Lopez, Castro, Slane, Ramirez-Ruiz

A SN remnant in SMC (SNR 0104-72.3) may be a result of a "prompt" SNIa based on enhanced Fe abundances and its association with a SF region; this SN remnant is thought to arise from a jet-driven bipolar core-collapse SN.  This SNR is highly elliptical relative to other nearby young SNRs, suggesting a CC SN origin.  Compare ejecta abundances derived from spectral fits to nucleosynthetic yields of type Ia and CC SNe, and find that the Fe, Ne and Si abundances are consistent with either a spherical CC SN of a 18-20 Msun progenitor, or an aspherical CC SN of a 25 Msun progenitor.  This suggests jet-driven SNe occur frequently in the low-metallicity environment of the SMC, consistent with the observational and theoretical work on broad-line Type Ic SNe and long-duration gamma-ray bursts.

1310.4506
Constraints on long-lived remnants of neutron star binary mergers from late-time radio observations of short duration gamma-ray bursts
Metzger, Bower

Coalescence of binary NSs can sometimes produce a massive NS that is potentially stable to gravitational collapse.  Such a remnant has been proposed as an explanation for the late X-ray emission observed following some short duration GRBs and as possible EM counterparts to the gravitational wave chirp.  A stable NS merger remnant necessarily possesses a large rotational energy > 1e52 erg, the majority of which is ultimately deposited into the surrounding circumburst medium (CBM) at mildly relativistic velocities.  Present radio observations of 7 short GRBs, some of which possessed temporally extended X-ray emission, on timescales of 1-3 years following the initial burst.  No radio sources detected (upper limit ~0.3 mJy at 1.4 GHz).  A basic model for the synchrotron emission from the blast wave is used to constrain the presence of a long-lived NS merger remnant in each system.  Depending on the GRB, non-detections translate into upper limits on the CBM density n<3e-2 to 3e-3 particles/cm^3 required for consistency with the remnant hypothesis.  Upper limits rule out a long-lived remnant in two GRB cases, but cannot rule out such a remnant in other systems due to their lower inferred CBM densities based on afterglow modeling or the lack of such constraints.  Additional VLA observations in the near future could place tighter limits on the presence of merger remnants in these system.  The population of long-lived NS merger remnants will also be constrained by their non-detection with upcoming radio transient surveys.