Astro Coffee

Suggested papers for
Tue, Apr 24, 2018, Thu, Apr 26, 2018, and Fri, Apr 27, 2018 at 11 am

18 Apr 2018

Resolving the ISM at the peak of cosmic star formation with ALMA - The distribution of CO and dust continuum in z~2.5 sub-millimetre galaxies

We use ALMA observations of four sub-millimetre galaxies (SMGs) at $z\sim2-3$ to investigate the spatially resolved properties of the inter-stellar medium (ISM) at scales of 1--5 kpc (0.1--0.6$''$). The velocity fields of our sources, traced by the $^{12}$CO($J$=3-2) emission, are consistent with disk rotation to first order, implying average dynamical masses of $\sim$3$\times10^{11}$M$_{\odot}$ within two half-light radii. Through a Bayesian approach we investigate the uncertainties inherent t...

Volunteer to discuss
Mark paper as discussed

19 Apr 2018

A 15.7-Minute AM CVn Binary Discovered in K2

We present the discovery of SDSS J135154.46-064309.0, a short-period variable observed using 30-minute cadence photometry in K2 Campaign 6. Follow-up spectroscopy and high-speed photometry support a classification as a new member of the rare class of ultracompact accreting binaries known as AM CVn stars. The spectroscopic orbital period of $15.65 \pm 0.12$\,minutes makes this system the fourth-shortest period AM CVn known, and the second system of this type to be discovered by the Kepler spacec...

Volunteer to discuss
Mark paper as discussed

19 Apr 2018

A Predicted Astrometric Microlensing Event by a Nearby White Dwarf

We used the Tycho-Gaia Astrometric Solution catalogue, part of the Gaia Data Release 1, to search for candidate astrometric microlensing events expected to occur within the remaining lifetime of the Gaia satellite. Our search yielded one promising candidate. We predict that the nearby DQ type white dwarf LAWD 37 (WD 1142-645) will lens a background star and will reach closest approach on November 11th 2019 ($\pm$ 4 days) with impact parameter $380\pm10$ mas. This will produce an apparent maximu...

Volunteer to discuss
Mark paper as discussed

17 Apr 2018

The Growth of Black Holes from Population III Remnants in the Renaissance Simulations

The formation of stellar mass black holes from the remnants of Population III stars provides a source of initial black hole seeds with the potential to grow into intermediate or, in rare cases, possibly supermassive black holes. We use the Renaissance simulation suite to follow the growth of over 15,000 black holes born into mini-haloes in the early Universe. The black holes populate haloes from 10^6 Msun up to 10^9 Msun. We find that all of the black holes display very inefficient growth. On a...

Volunteer to discuss
Mark paper as discussed

13 Apr 2018

Resolving the nuclear obscuring disk in the Compton-thick Seyfert galaxy NGC5643 with ALMA

We present ALMA Band 6 $^{12}$CO(2--1) line and rest-frame 232GHz continuum observations of the nearby Compton-thick Seyfert galaxy NGC5643 with angular resolutions 0.11-0.26arcsec (9-21pc). The CO(2--1) integrated line map reveals emission from the nuclear and circumnuclear region with a two-arm nuclear spiral extending 10arcsec on each side. The circumnuclear CO(2--1) kinematics can be fitted with a rotating disk, although there are regions with large residual velocities and/or velocity dispe...

Volunteer to discuss
Mark paper as discussed

16 Apr 2018

Magnetohydrodynamic Simulations of a Plunging Black Hole into a Molecular Cloud

Using two-dimensional magnetohydrodynamic simulations, we investigated the gas dynamics around a black hole plunging into a molecular cloud. In these calculations, we assumed a parallel-magnetic-field layer in the cloud. The size of the accelerated region is far larger than the Bondi-Hoyle-Lyttleton radius, being approximately inversely proportional to the Alfv\'en Mach number for the plunging black hole. Our results successfully reproduce the "Y" shape in position velocity maps of the "Bullet"...

Volunteer to discuss
Mark paper as discussed

16 Apr 2018

Radio interferometric observation of an asteroid occultation

The occultation of the radio galaxy 0141+268 by the asteroid (372) Palma on May 15, 2017 was observed using six antennas of the Very Long Baseline Array (VLBA). The shadow of Palma crossed Brewster, Washington. Owing to the wavelength used, and the size and the distance of the asteroid, a diffraction pattern in the Fraunhofer regime was observed. The measurement retrieves both the amplitude and the phase of the diffracted electromagnetic wave. This is the first astronomical measurement of the p...

Volunteer to discuss
Mark paper as discussed


No papers discussed yet

Sad Paper :(

Updated 2018/04/20 14:49:52