Search Publications
The association of the Hale sector boundary with RHESSI solar flares and active longitudes
Hannah, I. G.; Hudson, H. S.; Loumou, K.
Context. The heliospheric magnetic field (HMF) is structured into large sectors of positive and negative polarity. The parts of the boundary between these sectors where the change in polarity matches that of the leading-to-following sunspot polarity in that solar hemisphere, are called Hale sector boundaries (HSB).
Aims: We investigate the fl…
Propagating wave in active region-loops, located over the solar disk observed by the Interface Region Imaging Spectrograph
Zhang, J.; Zhang, B.; Hou, Y. J.
Aims: We aim to ascertain the physical parameters of a propagating wave over the solar disk detected by the Interface Region Imaging Spectrograph (IRIS).
Methods: Using imaging data from the IRIS and the Solar Dynamic Observatory (SDO), we tracked bright spots to determine the parameters of a propagating transverse wave in active region …
Far-infrared emission of massive stars
Krełowski, J.; Siebenmorgen, R.; Scicluna, P.
We present results of the analysis of a sample of 22 stars of spectral types from O7 to B5 and luminosity classes I-V for which spectra from the Infrared Spectrograph (IRS) of Spitzer are available. The IRS spectra of these stars are examined for signs of excess infrared (IR) emission by comparison with stellar atmospheric spectra. We find that th…
Spectral analysis of SXP59.0 during its 2017 outburst and properties of the soft excess in X-ray binary pulsars
Tiengo, A.; Mereghetti, S.; Sidoli, L. +3 more
We report the results provided by the XMM-Newton observation of the X-ray binary pulsar SXP59.0 during its most recent outburst in April 2017. The source was detected at fX(0.2-12 keV) = 8 × 10-11erg cm-2 s-1, one of its highest flux levels reported to date. The measured pulse period was Pspin…
Structure of the heliosheath from HSTOF energetic neutral atoms measurements
Hsieh, K. C.; Bzowski, M.; Hilchenbach, M. +4 more
Context. From the year 1996 until now, High energy Suprathermal Time Of Flight sensor (HSTOF) on board Solar and Heliospheric Observatory (SOHO) has been measuring the heliospheric energetic neutral atoms (ENA) flux between ±17° from the ecliptic plane. At present it is the only ENA instrument with the energy range within that of Voyager LECP ener…
A star-forming dwarf galaxy candidate in the halo of NGC 4634
Bomans, D. J.; Dettmar, R. -J.; Stein, Y. +3 more
Context. The halos of disk galaxies form a crucial connection between the galaxy disk and the intergalactic medium. Massive stars, H II regions, or dwarf galaxies located in the halos of galaxies are potential tracers of recent accretion and/or outflows of gas, and are additional contributors to the photon field and the gas phase metallicity.
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Dwarf irregular galaxy Leo A extends even farther, according to HST WFC3 photometry
Vansevičius, V.; Stonkutė, R.; Čeponis, M. +2 more
Context. Leo A is an isolated gas-rich dwarf irregular galaxy of low stellar mass and metallicity residing at the outskirts of the Local Group. Ages of the stellar populations in Leo A range from 10 Myr to 10 Gyr. A large stellar halo (up to the deprojected distance of 1.7 kpc) was discovered based on Subaru wide-field photometry of red giant bran…
The role of molecular gas in the nuclear regions of IRAS 00183-7111. ALMA and X-ray investigations of an ultraluminous infrared galaxy
Vignali, C.; Iwasawa, K.; Paladino, R. +2 more
Aims: We present a multi-frequency study of the ultraluminous infrared galaxy (ULIRG) IRAS 00183-7111 (z = 0.327), selected from the Spoon diagnostic diagram as a highly obscured active galactic nucleus (AGN) candidate. ALMA millimetre and X-ray observations are used; the main aim is to verify at what level the molecular gas, traced by the CO…
New transient Galactic bulge intermediate polar candidate XMMU J175035.2-293557
Haberl, F.; Ponti, G.; Hofmann, F. +1 more
Context. For the past decades, a rare subclass of cataclysmic variables (CV), with magnetised white dwarfs (WD) as accretors, has been studied. They are called intermediate polars (IP) and have been suggested to be the main contributors to the diffuse, hard X-ray emission close to the Galactic center (GC) and in the Galactic bulge (GB), because mo…
Investigating source confusion in PMN J1603-4904
Dauser, T.; Wilms, J.; Kadler, M. +8 more
PMN J1603-4904 is a likely member of the rare class of γ-ray emitting young radio galaxies. Only one other source, PKS 1718-649, has been confirmed so far. These objects, which may transition into larger radio galaxies, are a stepping stone to understanding AGN evolution. It is not completely clear how these young galaxies, seen edge-on, can produ…