Search Publications
Atomic data for astrophysics: Fe IX
Mason, H. E.; Del Zanna, G.; Storey, P. J. +1 more
We present the results of a new large-scale intermediate-coupling frame transformation R-matrix scattering calculation for electron collisional excitation of Fe ix. The target includes all the main configurations up to n = 5, to improve our earlier R-matrix and distorted-wave (DW) calculations for the n = 3,4 levels. Unlike similar calculations wh…
Multiwavelength observation of a large-scale flux rope eruption above a kinked small filament
Kumar, Pankaj; Cho, Kyung-Suk
We analyzed multiwavelength observations of a western limb flare (C3.9) that occurred in AR NOAA 111465 on 30 April 2012. The high-resolution images recorded by SDO/AIA 304, 1600 Å and Hinode/SOT Hα show the activation of a small filament (rising speed ~40 km s-1) associated with a kink instability and the onset of a C-class flare near …
The long-period Galactic Cepheid RS Puppis. III. A geometric distance from HST polarimetric imaging of its light echoes
Szabados, L.; Kervella, P.; Anderson, R. I. +8 more
As one of the most luminous Cepheids in the Milky Way, the 41.5-day RS Puppis is an analog of the long-period Cepheids used to measure extragalactic distances. An accurate distance to this star would therefore help anchor the zero-point of the bright end of the period-luminosity relation. But, at a distance of about 2 kpc, RS Pup is too far away f…
Physical structure of the photodissociation regions in NGC 7023. Observations of gas and dust emission with Herschel
Abergel, A.; Teyssier, D.; Zavagno, A. +16 more
Context. The determination of the physical conditions in molecular clouds is a key step towards our understanding of their formation and evolution of associated star formation. We investigate the density, temperature, and column density of both dust and gas in the photodissociation regions (PDRs) located at the interface between the atomic and col…
A subarcsecond study of the hot molecular core in G023.01-00.41
Menten, K. M.; Sanna, A.; Molinari, S. +5 more
Context. Searching for disk-outflow systems in massive star-forming regions is a key to assessing the main physical processes in the recipe of massive star formation.
Aims: We have selected a hot molecular core (HMC) in the high-mass star-forming region G023.01-00.41, where VLBI multi-epoch observations of water and methanol masers have sugge…
Polycyclic aromatic hydrocarbon feature deficit of starburst galaxies in the AKARI North Ecliptic Pole Deep field
Inami, H.; Armus, L.; Serjeant, S. +6 more
We study the behaviour of polycyclic aromatic hydrocarbon (PAH) emission in galaxies at z = 0.3-1.4 using 1868 samples from the revised catalogue of AKARI North Ecliptic Pole Deep survey. The continuous filter coverage at 2-24 µm makes it possible to measure 8 µm luminosity, which is dominated by PAH emission, for galaxies at up to z =…
Pair separation of magnetic elements in the quiet Sun
Gošić, M.; Orozco Suárez, D.; Bellot Rubio, L. +5 more
The dynamic properties of the quiet Sun photosphere can be investigated by analyzing the pair dispersion of small-scale magnetic fields (i.e., magnetic elements). By using 25 h-long Hinode magnetograms at high spatial resolution (0.3 arcsec), we tracked 68 490 magnetic element pairs within a supergranular cell near the disk center. The computed pa…
Discovery of O VII line emitting gas in elliptical galaxies
Fabian, Andrew C.; Sanders, Jeremy S.; Finoguenov, Alexis +7 more
In the cores of ellipticals, clusters, and groups of galaxies, the gas has a cooling time shorter than 1 Gyr. It is possible to probe cooling flows through the detection of Fe XVII and O VII emission lines, but so far O VII has not been detected in any individual object. The Reflection Grating Spectrometers (RGS) aboard XMM-Newton are currently th…
The problematically short superwind of OH/IR stars. Probing the outflow with the 69 µm spectral band of forsterite
Waters, L. B. F. M.; Blommaert, J. A. D. L.; Min, M. +4 more
Aims: Spectra of OH/IR stars show prominent spectral bands of crystalline olivine (Mg(2 - 2x)Fe(2x)SiO4). To learn more about the timescale of the outflows of OH/IR stars, we study the spectral band of crystalline olivine at 69 µm.
Methods: The 69 µm band is of interest because its width and p…
Herschel observations of gamma-ray burst host galaxies: implications for the topology of the dusty interstellar medium
Palazzi, E.; Greiner, J.; Hunt, L. K. +11 more
Long-duration gamma-ray bursts (GRBs) are indisputably related to star formation, and their vast luminosity in gamma rays pin-points regions of star formation independent of galaxy mass, out to the epoch of re-ionisation. As such, GRBs provide a unique tool for studying star forming galaxies out to high-z independent of luminosity. Most of our und…