Search Publications
AKARI detections of hot dust in luminous infrared galaxies. Search for dusty active galactic nuclei
Ohyama, Y.; Matsuhara, H.; Oyabu, S. +10 more
Aims: We present a new sample of active galactic nuclei (AGNs) identified using the catalog of the AKARI Mid-infrared (MIR) All-Sky Survey. Our MIR search has the advantage of detecting AGNs that are obscured at optical wavelengths by extinction.
Methods: We first selected AKARI 9 µm excess sources with F(9 µm)/F(KS
XMM-Newton investigations of the Lambda Orionis star-forming region (XILO). I. The young cluster Collinder 69
Bayo, A.; Huélamo, N.; Barrado, D. +6 more
Context. This is the first paper of a series devoted to the Lambda Orionis star-forming region, Orion's Head, from the X-ray perspective. Our final aim is to provide a comprehensive view of this complex region, which includes several distinct associations and dark clouds.
Aims: We aim to uncover the population of the central, young star clust…
Flare occurrence and the spatial distribution of the magnetic helicity flux
Romano, P.; Zuccarello, F.
Context. The accumulation of magnetic helicity via emergence of new magnetic flux and/or shearing photospheric motions is considered an important tool for understanding the processes that lead to eruptive phenomena.
Aims: We highlight a specific aspect of the magnetic helicity accumulation, providing new observational evidence of the role pla…
Photon dominated regions in NGC 3603. [CI] and mid-J CO line emission
Schieder, R.; Ossenkopf, V.; Bertoldi, F. +32 more
Aims: We aim at deriving the excitation conditions of the interstellar gas as well as the local FUV intensities in the molecular cloud surrounding NGC 3603 to get a coherent picture of how the gas is energized by the central stars.
Methods: The NANTEN2-4 m submillimeter antenna is used to map the [CI] 1-0, 2-1 and CO 4-3, 7-6 lines in a …
The outer rings of SN 1987A
Lundqvist, P.; Tziamtzis, A.; Gröningsson, P. +1 more
Aims: We investigate the physical properties and structure of the outer rings of SN 1987A to understand their formation and evolution.
Methods: We used low resolution spectroscopy from VLT/FORS1 and high resolution spectra from VLT/UVES to estimate the physical conditions in the outer rings, using nebular analysis for emission lines such…
Optical multiband surface photometry of a sample of Seyfert galaxies. I. Large-scale morphology and local environment analysis of matched Seyfert and inactive galaxy samples
Mihov, B.; Slavcheva-Mihova, L.
Context. Parallel analysis of the large-scale morphology and local environment of matched active and control galaxy samples plays an important role in studies of the fueling of active galactic nuclei.
Aims: We carry out a detailed morphological characterization of a sample of 35 Seyfert galaxies and a matched sample of inactive galaxies in or…
2D radiative-magnetohydrostatic model of a prominence observed by Hinode, SoHO/SUMER and Meudon/MSDP
Heinzel, P.; Schmieder, B.; Schwartz, P. +2 more
Aims: Prominences observed by Hinode show very dynamical and intriguing structures. To understand the mechanisms that are responsible for these moving structures, it is important to know the physical conditions that prevail in fine-structure threads. In the present work we analyse a quiescent prominence with fine structures, which exhibits dy…
Mid-infrared interferometric monitoring of evolved stars. The dust shell around the Mira variable RR Aquilae at 13 epochs
Wittkowski, M.; Ohnaka, K.; Karovicova, I. +3 more
Aims: We present a unique multi-epoch infrared interferometric study of the oxygen-rich Mira variable RR Aql in comparison to radiative transfer models of the dust shell. We investigate flux and visibility spectra at 8-13 µm with the aim of better understanding the pulsation mechanism and its connection to the dust condensation sequence…
Evolution of microflares associated with bright points in coronal holes and in quiet regions
Curdt, W.; Innes, D. E.; Teriaca, L. +1 more
Aims: We aim to find similarities and differences between microflares at coronal bright points found in quiet regions and coronal holes, and to study their relationship with large scale flares.
Methods: Coronal bright points in quiet regions and in coronal holes were observed with Hinode/EIS using the same sequence. Microflares associate…
The X-ray spectral signatures from the complex circumnuclear regions in the Compton thick AGN NGC 424
Bianchi, S.; Piconcelli, E.; Iwasawa, K. +4 more
Aims: Most of our knowledge of the circumnuclear matter in Seyfert galaxies is based on the X-ray spectra of the brightest Compton-thick Seyfert 2 galaxies. The complete obscuration of the nuclear radiation in these sources allows us to study all the components arising from reprocessing of the primary continuum in the circumnuclear matter in …