Search Publications
Resolving the circumbinary dust disk surrounding HH 30
Pety, J.; Gueth, F.; Guilloteau, S. +1 more
Context: The jet-disk connection is an important part of the star formation process. HH 30 is a rare and beautiful example of a system exhibiting a flared edge-on disk, an optical jet and a CO molecular outflow. A recent analysis of the jet wiggling has revealed that the central star is in reality a binary object. Therefore, the dust and gas disk …
Dynamical properties of a large young disk galaxy at z = 2.03
Wuyts, S.; Franx, M.; van der Werf, P. P. +3 more
Context: The study of high redshift Tully-Fisher relations (TFRs) is limited by the use of long slit spectrographs, rest frame B band and star formation selected galaxies.
Aims: We try to circumvent these issues by using integral field spectroscopy (SINFONI), by studying the rest frame K band and stellar mass TFR, and by selecting targets with…
The Seyfert 1 Galaxy Mrk 335 at a very low flux state: mapping the soft X-ray photoionised gas
Guainazzi, M.; Santos-Lleo, M.; Nucita, A. +1 more
Context: This paper reports on an XMM-Newton observation of the Seyfert 1 Galaxy Mrk 335 performed as a target of opportunity when the source was in an unusually low flux state.
Aims: The low level of continuum emission unveiled an underlying line-rich soft X-ray spectrum, which can be studied with the Reflection Grating Spectrometer.
Meth…
Evolution of the flaring active region NOAA 10540 as a sequence of nonlinear force-free field extrapolations
Wiegelmann, T.; Thalmann, J. K.
Context: The solar corona is structured by magnetic fields. As direct measurements of the coronal magnetic field are not routinely available, it is extrapolated from photospheric vector magnetograms. When magnetic flux emerges from below the solar surface and expands into the corona, the coronal magnetic field is destabilized, leading to explosive…
Temporal variations in the Sun's rotational kinetic energy
Antia, H. M.; Gough, D. O.; Chitre, S. M.
Aims: We study the variation of the angular momentum and the rotational kinetic energy of the Sun, and associated variations in the gravitational multipole moments, on a timescale of the solar cycle.
Methods: These quantities are determined by inverting helioseismic rotational splitting data obtained by the Global Oscillation Network Group and…
Variations of the solar granulation motions with height using the GOLF/SoHO experiment
Jiménez-Reyes, S. J.; García, R. A.; Mathur, S. +2 more
Context: Below 1 mHz, the power spectrum of helioseismic velocity measurements is dominated by the spectrum of convective motions (granulation and supergranulation) and it is difficult to detect the low-order acoustic modes and gravity modes.
Aims: We attempt to understand more clearly the behavior of solar granulation as a function of observi…
The long-term X-ray variability properties of AGNs in the Lockman Hole region
Papadakis, I. E.; Georgantopoulos, I.; Markowitz, A. +2 more
Context: We present the results from a detailed X-ray variability analysis of 66 AGN in the Lockman Hole, which have optical spectroscopic identifications.
Aims: We compare, quantitatively, their variability properties with the properties of local AGN, and we study the “variability - luminosity” relation as a function of redshift, and the “var…
Young star clusters in interacting galaxies - NGC 1487 and NGC 4038/4039
Lehnert, M. D.; Vacca, W. D.; Chandar, R. +3 more
We estimate the dynamical masses of several young (≈10 Myr) massive star clusters in two interacting galaxies, NGC 4038/4039 (“The Antennae”) and NGC 1487, under the assumption of virial equilibrium. These are compared with photometric mass estimates from K-band photometry assuming a standard Kroupa IMF. The clusters were selected to have near-inf…
Density structure of an active region and associated moss using Hinode/EIS
Young, P. R.; Mason, H. E.; Del Zanna, G. +1 more
Context: Studying the problem of active region heating requires precise measurements of physical plasma parameters such as electron density, temperature, etc. It is also important to understand the relationship of coronal structures with the magnetic field. The Extreme-ultraviolet Imaging Spectrometer (EIS) aboard Hinode provides a rare opportunit…
Tracing jet-ISM interaction in young AGN: correlations between [O III] λ 5007 Å and 5-GHz emission
Labiano, A.
Aims: I study the interaction between young AGN and their host galaxies based on their ionized gas and radio emission, and analyze possible implications for radio galaxy evolution.
Methods: The [O III] λ 5007 Å line and 5-GHz radio properties are compared and studied for a large, representative sample of GPS and CSS (i.e., young) quasars and r…