Search Publications

Dust charging in the Enceladus torus

Yaroshenko, V. V.; Lühr, H.; Miloch, W. J.

Employing the parameter space, consistent with available Cassini data, dust charging is studied in the near-Enceladus plasma with special focus on the region close to the moon's plume. The emphasis is on the role of dust size distribution and grain density, the electron temperature, fraction of the hot electrons, and multi-ion composition includin…

Turbulent dynamics inside the cavity of hot flow anomaly

Dandouras, I.; Facskó, G.; Kovács, P.

In this paper the turbulent dynamics of a hot flow anomaly (HFA) event is investigated. The HFAs are transient plasma disturbances generated by the interaction of the bow shock (BS) and a tangential discontinuity (TD) embedded in the solar wind. The typical changes of the plasma parameters inside HFAs (increased plasma temperature, low bulk veloci…

High spatial resolution of the mid-infrared emission of the Compton-thick type 2 Seyfert galaxy, Markarian 3

Pastoriza, M. G.; Winge, Cláudia; Sales, Dinalva A. +2 more

The mid-infrared (MIR) spectra observed with Gemini/Michelle have been used to study the nuclear region of the Compton-thick type 2 Seyfert galaxy, Markarian 3 (Mrk 3), at a spatial resolution of ∼200 pc. No polycyclic aromatic hydrocarbon emission bands were detected in the N-band spectrum of Mrk 3. However, intense [Ar III] 8.99 µm, [S IV]…

An initial investigation of the long-term trends in the fluxgate magnetometer (FGM) calibration parameters on the four Cluster spacecraft

Carr, C. M.; Brown, P.; Oddy, T. M. +3 more

Over the course of more than 10 years in operation, the calibration parameters of the outboard fluxgate magnetometer (FGM) sensors on the four Cluster spacecraft are shown to be remarkably stable. The parameters are refined on the ground during the rigorous FGM calibration process performed for the Cluster Active Archive (CAA). Fluctuations in som…

The Temperature of Quiescent Streamers during Solar Cycles 23 and 24

Landi, E.; Testa, P.

Recent in-situ determinations of the temporal evolution of the charge state distribution in the fast and slow solar wind have shown a general decrease in the degree of ionization of all the elements in the solar wind along solar cycles 23 and 24. Such a decrease has been interpreted as a cooling of the solar corona which occurred during the declin…

Probing large-scale structure with large samples of X-ray selected AGN. I. Baryonic acoustic oscillations

Sunyaev, Rashid; Gilfanov, Marat; Hütsi, Gert +1 more

We investigate the potential of large X-ray-selected AGN samples for detecting baryonic acoustic oscillations (BAO). Though AGN selection in X-ray band is very clean and efficient, it does not provide redshift information, and thus needs to be complemented with an optical follow-up. The main focus of this study is (i) to find the requirements need…

A New Catalog of Silicate Carbon Stars

Suh, Kyung-Won; Kwon, Young-Joo

Application of the Baade-Wesselink method to a pulsating cluster Herbig Ae star: H254 in IC348

Ripepi, V.; Molinaro, R.; Palla, F. +6 more

In this paper we present new photometric and radial velocity data for the PMS δ Sct star H254, member of the young cluster IC 348. Photometric V, R_C, I_C light curves were obtained at the Loiano and Asiago telescopes. The radial velocity data were acquired by means of the SARG@Telescopio Nazionale Galileo spectrograph. High-re…

Segmentation of coronal features to understand the solar EUV and UV irradiance variability

Chitta, L. P.; Verbeeck, C.; Giono, G. +8 more

Context. The study of solar irradiance variability is of great importance in heliophysics, the Earth's climate, and space weather applications. These studies require careful identifying, tracking and monitoring of active regions (ARs), coronal holes (CHs), and the quiet Sun (QS).
Aims: We studied the variability of solar irradiance for a peri…

A Photon-dominated Region Model for the FIR Mid-J CO Ladder with Universal Rotational Temperature in Star Forming Regions

Lee, Jeong-Eun; Bergin, Edwin A.; Lee, Seokho +1 more

A photon-dominated region (PDR) is one of the leading candidate mechanisms for the origin of warm CO gas with near universal ~300 K rotational temperature inferred from the CO emission detected toward embedded protostars by Herschel/PACS. We have developed a PDR model in general coordinates, where we can use the most adequate coordinate system for…