Related papers: Accretion-ejection connection in the young brown d…

The time evolution of the dependence of the mass accretion rate with the stellar mass and the disk mass represents a fundamental way to understand the evolution of protoplanetary disks and the formation of planets. In this work, we present…

Accreting neutron stars in low-mass X-ray binaries show outflows -- and sometimes jets -- in the general manner of accreting black holes. However, the quantitative link between the accretion flow (traced by X-rays) and outflows and/or jets…

The protostar IRAS 15398-3359 is associated with a bipolar molecular outflow ejected in an nearly northeast-southwest (NE-SW) direction which has been extensively studied. It has been suggested previous episodic accretion events by this…

We present the results of our quasi-simultaneous radio, sub-mm, infrared, optical and X-ray study of the Galactic black hole candidate X-ray binary MAXI J1836-194 during its 2011 outburst. We consider the full multi-wavelength spectral…

We present the results of the analysis of LR optical-NIR spectra (0.6-2.4 um) of a sample 47 YSOs in the ChaI and II star-forming clouds. These data are part of the POISSON project (Protostellar Optical-Infrared Spectral Survey on NTT). The…

We present an optical/near-IR survey of 11 variable young stars (EXors and EXor candidates) aimed at deriving and monitoring their accretion properties. About 30 optical and near-infrared spectra ($\Re$ $\sim$ 1500-2000) were collected…

Young stars and planetary systems form in molecular clouds. For classical T Tauri stars (CTTS, F-K type precursors) the accretion disk does not reach down to the central star, but it is truncated near the co-rotation radius. The inner edge…

In recent years, much effort has been devoted to unraveling the connection between the accretion flow and the jets in accreting compact objects. In the present work, we report new constraints on these issues, through the long term study of…

During the early stages of star formation, accretion processes such as infall from the envelope and molecular streamers, and ejection of matter through winds and jets take place simultaneously. The Class 0/I binary [BHB2007] 11 shows…

Low-mass pre-main sequence (PMS) stars are strong X-ray sources, because they possess hot corona like their older main-sequence counterparts. Unique to young stars, however, are X-rays from accretion and outflows, and both processes are of…

In $2016-17$, the Galactic transient black hole candidate GRS 1716-249 exhibited an outburst event after a long period of quiescence of almost 23 years. The source remained in the outbursting phase for $\sim 9$ months. We study the spectral…

We present the first observations of a probable brown dwarf, obtained with the new spectrograph X-shooter mounted on the UT2@VLT. The target (2MASS J053825.4-024241) is a 0.06 Msun object in the star-formation region sigma Orionis. The…

This letter reports statistically significant changes in the equivalent widths of MgII and CaII lines in the dusty and polluted white dwarf WD 0106-328, based on six epochs of spectroscopy using the VLT and Keck spanning 25 yr. Furthermore,…

We report on the discovery of the young, nearby, brown dwarf 2MASS J0041353$-$562112. The object has a spectral type of M7.5, it shows Li absorption and signatures of accretion, which implies that it still has a disk and suggests an age…

Accretion among planets is a poorly understood phenomenon, due to lack of both observational and theoretical studies. Detection of emission lines from accreting gas giants facilitate detailed investigations into this process. This work…

We present a detailed spectroscopic investigation of the young eruptive star PV Cep, to improve our understanding of its nature and characterise its circumstellar environment after its last outburst in 2004. The analysis of our…

We reexamine a previously proposed model for thermal pressure acceleration of collimated outflows in young stellar objects (YSO). We are motivated by new results from recent X-ray observations of YSO. These show that there is essentially no…

We have undertaken the largest survey for outflows within the Galactic Plane using simultaneously observed 13CO and C18O data. 325 out of a total of 919 ATLASGAL clumps have data suitable to identify outflows, and 225 (69+-3%) of them show…

In studies of accreting black holes in binary systems, empirical relations have been proposed to quantify the coupling between accretion processes and ejection mechanisms. These processes are probed respectively by means of X-ray and…

We present numerical hydrodynamical modeling of the effects of a giant planet or brown dwarf companion orbiting within the extended atmosphere and wind formation zone of an approximately solar-mass Mira variable star. The large-scale,…