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A search for clustering around Herbig Ae/Be stars - II. Atlas of the observed sources

We present large field infrared images of a sample of 45 Herbig Ae/Be stars. Stellar parameters, such as age and luminosity, have been derived for all of them in a consistent way. The images have been used to identify stellar groups or clusters associated with the Herbig Ae/Be star. The results presented in this paper form the database for a study of clustering around...

X-rays from jet-driving protostars and T Tauri stars

Aims.We study jet-driving protostars and T Tau stars to characterize their X-ray emission. We seek soft spectral components that may be due to shock emission, and search for soft, shock-induced emission displaced from the stellar position. Methods.We study two stellar samples, the first consisting of lightly absorbed T Tau stars with strong jets, the other containing protostars...

CoRoT 102699796, the first metal-poor Herbig Ae pulsator: a hybrid δ Sct–γ Dor variable?*,†

We present the analysis of the time series observations of CoRoT 102699796 obtained by the Convection, Rotation and planetary Transits (CoRoT) satellite that show the presence of five independent oscillation frequencies in the range 3.6–5 c d−1. Using spectra acquired with FLAMES@VLT, we derive the following stellar parameters: spectral type F1V, Teff= 7000 ± 200 K, log (g) = 3.8...

Pre-main-sequence stars in the star-forming complex Sh 2-284

Located at the Galactic anticentre, Sh 2-284 is an H ii region that harbours several young open clusters. Dolidze 25, a rare metal-poor (Z∼ 0.004) young cluster, is one of these. Given its association with Sh 2-284, it is reasonable to assume a low metallicity for the whole H ii region. Sh 2-284 is expected to host a significant population of pre-main-sequence (PMS) stars of both...

Characterisation of irradiated thin silicon sensors for the CMS phase II pixel upgrade

The high luminosity upgrade of the Large Hadron Collider, foreseen for 2026, necessitates the replacement of the CMS experiment’s silicon tracker. The innermost layer of the new pixel detector will be exposed to severe radiation, corresponding to a 1 MeV neutron equivalent fluence of up to \(\Phi _{eq} = 2 \times 10^{16}\) cm\(^{-2}\), and an ionising dose of \({\approx } 5\) MGy...

New pre-main sequence candidates in the Taurus-Auriga star forming region

Aims.We have studied the X-ray source population of the Taurus Molecular Cloud (TMC) to search for new members of the Taurus-Auriga star forming region.Methods.Candidate members have been selected among the X-ray sources detected in 24 fields of the XMM-Newton Extended Survey of the Taurus Molecular Cloud, having an IR counterpart in the 2MASS catalog, based on color–magnitude...

A theoretical approach for the interpretation of pulsating PMS intermediate-mass stars

Context.The investigation of the pulsation properties of pre-main-sequence intermediate-mass stars is a promising tool to evaluate the intrinsic properties of these stars and to constrain current evolutionary models. Many new candidates of this class have been discovered during the last decade and very accurate data are expected from space observations obtained for example with...

Chandra X-ray observations of the young stellar cluster NGC 6193 in the Ara OB1 association

A 90-ks Chandra High Energy Transmission Grating observation of the young stellar cluster NGC 6193 in the southern Ara OB1 association detected 43 X-ray sources in a 2 × 2 arcmin2 core region centred on the massive O stars HD 150135 (O6.5 V) and HD 150136 (O3 + O6V). The cluster is dominated by exceptionally bright X-ray emission from the two O stars, which are separated by only...

A deep wide-field optical survey in the young open cluster Collinder 359

We present the first deep, optical, wide-field imaging survey of the young open cluster Collinder 359, complemented by near-infrared follow-up observations. This study is part of a large programme aimed at examining the dependence of the mass function on environment and time. We have surveyed 1.6 square degrees in the cluster, in the I and z filters, with the CFH12K camera on the...

Spectral properties of X-ray bright variable sources in the Taurus molecular cloud

Aims.We analyze 19 bright variable X-ray sources detected in the XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST), to characterize the variations with time of their coronal properties and to derive information on the X-ray emitting structures.Methods.We performed time-resolved spectroscopy of the EPIC PN and MOS spectra of the XEST sources, using a model with one...

Oscillations in the PMS δ Scuti star V346 Ori

We report the discovery of periodicities in the light curve of the Pre-Main Sequence (PMS) Herbig Ae star V346 Ori. We interpret variations in the light curve of the star as the superposition of at least two periodic signals that result from δ Scuti-type stellar oscillations. The computation of linear non-adiabatic radial pulsation models for PMS stars reproduces these periods...

The EChO science case

Alcaino 28 & E. Oliva 56 & G. Orton 18 & F. Palla 56 & M. Pancrazzi 48 & E. Pantin 46 & V. Parmentier 22 & 32 Université de Bordeaux, Bordeaux, France 33 INAF, Torino, Italy 34 CAB, Madrid, Spain

Collider aspects of flavor physics at high Q

. Moreau M. Mhlleitner M. Mntel A. Onofre E. zcan F. Palla L. Panizzi S. Pearanda R. Pittau A. Pukhov M. Raidal A.R. Raklev L. Rebane F.M. Renard D. Restrepo Z. Roupas R. Santos S. Schumann G. Servant F

Search for neutral Higgs bosons decaying into four taus at LEP2

, T. Boccali, L. Foa`, A. Giammanco, A. Giassi, F. Ligabue, A. Messineo, F. Palla, G. Sanguinetti, A. Sciab`a, G. Sguazzoni, P. Spagnolo, R. Tenchini, A. Venturi and P.G. Verdini Dipartimento di Fisica