Search
Now showing items 341-350 of 485
A Spatially Resolved Radio Spectral Index Study of the Dwarf Irregular Galaxy NGC\,1569
(2018-04-21)
We study the resolved radio continuum spectral energy distribution of the dwarf irregular galaxy, NGC 1569, on a beam-by-beam basis to isolate and study its spatially resolved radio emission characteristics. Utilizing ...
Remnant radio-loud AGN in the Herschel-ATLAS field
(2018-04-21)
Only a small fraction of observed active galactic nuclei (AGN) display large-scale radio emission associated with jets, yet these radio-loud AGN have become increasingly important in models of galaxy evolution. In determining ...
AD Leonis : Radial velocity signal of stellar rotation or spin-orbit resonance?
(2018-04-16)
AD Leonis is a nearby magnetically active M dwarf. We find Doppler variability with a period of 2.23 days, as well as photometric signals: (1) a short-period signal, which is similar to the radial velocity signal, albeit ...
LOFAR-Boötes : Properties of high- and low-excitation radio galaxies at 0.5 < z < 2.0
(2018-04-11)
This paper presents a study of the redshift evolution of radio-loud active galactic nuclei (AGN) as a function of the properties of their galaxy hosts in the Boötes field. To achieve this we match low-frequency radio sources ...
The Initial mass function of the first stars inferred from extremely metal-poor stars
(2018-04-11)
We compare the elemental abundance patterns of ~200 extremely metal-poor (EMP; [Fe/H] < −3) stars to the supernova yields of metal-free stars, in order to obtain insights into the characteristic masses of the first (Population ...
The ALMA view of GMCs in NGC 300 : Physical Properties and Scaling Relations at 10 pc Resolution
(2018-04-09)
We have conducted a 12CO(2-1) survey of several molecular gas complexes in the vicinity of H ii regions within the spiral galaxy NGC 300 using the Atacama Large Millimeter Array (ALMA). Our observations attain a resolution ...
A formation timescale of the Galactic halo from Mg isotopes in dwarf stars
(2018-04-04)
We determine magnesium isotopic abundances of metal-poor dwarf stars from the galactic halo, to shed light on the onset of asymptotic giant branch (AGB) star nucleosynthesis in the galactic halo and constrain the timescale ...
MUSE observations of the counter-rotating nuclear ring in NGC 7742
(2018-04-01)
Aims. We present results from MUSE observations of the nearly face-on disk galaxy NGC 7742. This galaxy hosts a spectacular nuclear ring of enhanced star formation, which is unusual in that it is hosted by a non-barred ...
A 1.3 mm SMA Survey of 29 Variable Young Stellar Objects
(2018-04-01)
Context. Young stellar objects (YSOs) may undergo periods of active accretion (outbursts), during which the protostellar accretion rate is temporarily enhanced by a few orders of magnitude. Whether or not these accretion ...
A simulation-based analytic model of radio galaxies
(2018-04-01)
I derive and discuss a simple semi-analytical model of the evolution of powerful radio galaxies which is not based on assumptions of self-similar growth, but rather implements some insights about the dynamics and energetics ...