Day 575

Friday.  Sunday.

1401.0535
A millisecond pulsar in a stellar triple system
Random et al

Gravitational three-body systems: studied for 100s of years, common in our Galaxy, show complex orbital interactions, which can constrain compositions, masses and interior structures of the bodies, and test theories of gravity if sufficiently precise measurements available.  Report precision timing and multi-wavelength observations of PSR J0337+1715, a millisecond pulsar in a hierarchical triple system with two other stars.  Strong gravitational interactions are apparent and provide the masses of the pulsar (1.4378 Msun), and the two WD companions (0.29651Msun and 0.4101 Msun), as well as they inclinations of the orbits (both approximately 39.2 degrees).  The unexpectedly coplanar and nearly circular orbits indicate a complex and exotic evolutionary past that differs from those of known stellar systems.  The gravitational field of the outer WD strongly accelerates the inner binary containing the NS, and the system will thus provide an dial laboratory in which to test the strong equivalence principle of GR.

1401.0536
Similarity of ionized gas nebulae around unobscured and obscured quasars
Liu, Zakamska, Greene

Quasar feedback is suspected to play a key role in the evolution of massive galaxies, by removing or reheating gas in quasar host galaxies and thus limiting the amount of star formation.  Continue investigation of quasar-driven winds on galaxy-wide scales.  Integral field unit on type 1 (unobscured) quasars to determine the morphology and kinematics of ionized gas around these objects, mostly via O III 5007 emission line.  Find that ionized gas nebulae extend out to ~13 kpc from the quasar, that they are smooth an round, and that their kinematics are strikingly similar to those of ionized gas around type 2 (obscured) quasars with matched [O III] luminosity, with marginal evidence that nebulae around unobscured quasars are slightly more compact.  In samples of obscured and unobscured quasars carefully matched in O III matched luminosity, find support for the standard geometry-based unification model of AGN, in that the intrinsic properties of quasars, of their hosts and of their ionized gas appear to be very similar.  Given the apparent ubiquity of extended ionized regions, forced to conclude that either the quasar is at least partially illuminating preexisting gas or that both samples of quasars are seen during advanced stages [?] of quasar feedback.  In the latter case, may be biased by the OIII selection against quasars in the early "blow-out" phase, for example due to dust obscuration.

1401.0537
Probing dark energy with lensing magnification in photometric surveys
Schneider

Present an estimator for the angular cross-correlation of two tracers of the cosmological LSS that utilizes z info to isolate separate physical contributions.  The estimator is derived by solving the Limber equation for a re-wieghting of the FG tracer that nulls either clustering or lensing contributions to the cross-correlation function.  Applied to future photometric surveys, the estimator can enhance the measurement of gravitational lensing magnification effects to provide a competitive independent constraint on the DE EoS.