Search Publications
Evidence of scale height variations in the Martian ionosphere over the solar cycle
Lester, M.; Milan, S. E.; Morgan, D. D. +5 more
Solar cycle variations in solar radiation create density changes in any planetary ionosphere, which are well established in the Earth's case. At Mars, however, the ionospheric response to such changes is not well understood. We show the solar cycle impact on the topside ionosphere of Mars, using data from the Mars Advance Radar for Subsurface and …
Quiescent Compact Galaxies at Intermediate Redshift in the COSMOS Field. II. The Fundamental Plane of Massive Galaxies
Geller, Margaret J.; Damjanov, Ivana; Chilingarian, Igor +1 more
We examine the relation between surface brightness, velocity dispersion, and size—the fundamental plane (FP)—for quiescent galaxies at intermediate redshifts in the COSMOS field. The COSMOS sample consists of ∼150 massive quiescent galaxies with an average velocity dispersion of σ ∼ 250 km s-1 and redshifts between 0.2 < z < 0.8. …
An Observational Revisit of Band-split Solar Type-II Radio Bursts
Li, Gang; Chen, Yao; Feng, Shiwei +3 more
The band split of solar type II radio bursts, discovered several decades ago, is a fascinating phenomenon, with the type II lanes exhibiting two almost parallel sub-bands with similar morphology. The underlying split mechanism remains elusive. One popular interpretation is that the splitting bands are emitted from the shock upstream and downstream…
Identifying the source region of plasmaspheric hiss
Laakso, Harri; Masson, Arnaud; Escoubet, Philippe +4 more
The presence of the plasmaspheric hiss emission around the Earth has been known for more than 50 years, but its origin has remained unknown in terms of source location and mechanism. The hiss, made of whistler mode waves, exists for most of the time in the plasmasphere and is believed to control the radiation belt surrounding the Earth which makes…
A CO-rich merger shaping a powerful and hyperluminous infrared radio galaxy at z = 2: the Dragonfly Galaxy
Pentericci, L.; Colina, L.; Villar-Martín, M. +17 more
In the low-redshift Universe, the most powerful radio sources are often associated with gas-rich galaxy mergers or interactions. We here present evidence for an advanced, gas-rich (`wet') merger associated with a powerful radio galaxy at a redshift of z ∼ 2. This radio galaxy, MRC 0152-209, is the most infrared-luminous high-redshift radio galaxy …
Modelling the atmosphere of the carbon-rich Mira RU Virginis
Groenewegen, M. A. T.; Hron, J.; Paladini, C. +3 more
Context. We study the atmosphere of the carbon-rich Mira
Aims: The aim of this work is to analyse the atmosphere of the carbon-rich Mira RU Vir with hydrostatic and dynamic models, in this way deepening the knowledge of the dy…
Circumstellar discs in Galactic centre clusters: Disc-bearing B-type stars in the Quintuplet and Arches clusters
Ghez, A. M.; Anderson, J.; Brandner, W. +7 more
We investigate the circumstellar disc fraction as determined from L-band excess observations of the young, massive Arches and Quintuplet clusters residing in the central molecular zone of the Milky Way. The Quintuplet cluster was searched for L-band excess sources for the first time. We find a total of 26 excess sources in the Quintuplet cluster, …
Spectroscopic Observations of a Coronal Loop: Basic Physical Plasma Parameters Along the Full Loop Length
Gupta, G. R.; Tripathi, Durgesh; Mason, Helen E.
Coronal loops are the basic structures of the solar transition region and corona. Understanding of the physical mechanisms behind the loop heating, plasma flows, and filling are still considered a major challenge in solar physics. The mechanism(s) should be able to supply mass to the corona from the chromosphere and to heat the plasma over 1 MK wi…
Quadrupole-octopole alignment of CMB related to the primordial power spectrum with dipolar modulation in anisotropic spacetime
Wang, Sai; Chang, Zhe; Li, Xin
The WMAP and Planck observations show that the quadrupole and octopole orientations of the CMB might align with each other. We reveal that the quadrupole-octopole alignment is a natural implication of the primordial power spectrum in an anisotropic spacetime. The primordial power spectrum is presented with a dipolar modulation. We obtain the privi…
A Theoretical Study on the Vibrational Spectra of Polycyclic Aromatic Hydrocarbon Molecules with Aliphatic Sidegroups
Zhang, Yong; Kwok, Sun; Sadjadi, SeyedAbdolreza
The role of aliphatic side groups in the formation of astronomical unidentified infrared emission (UIE) features is investigated by applying the density functional theory to a series of molecules with mixed aliphatic-aromatic structures. The effects of introducing various aliphatic groups to a fixed polycyclic aromatic hydrocarbon (PAH) core (oval…