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Context. Being the most numerous and oldest stars in the galaxy, M dwarfs are objects of great interest for exoplanet searches. The presence of molecules in their atmosphere complicates our understanding of their atmospheric properties. But great advances have recently been made in the modeling of M dwarfs due to the revision of solar abundances. Aims. We aim to determine stellar parameters of M dwarfs using high resolution spectra (R ∼ 90 000) simultaneously in the visible and the near-infrared. The high resolution spectra and broad wavelength coverage provide an unique opportunity to understand the onset of dust and cloud formation at cool temperatures. Furthermore, this study will help in understanding the physical processes which occur in a cool atmospheres, particularly, the redistribution of energy from the optical to the near-infrared. Methods. The stellar parameters of M dwarfs in our sample have been determined by comparing the high resolution spectra both in the optical and in the near-infrared simultaneously observed by CARMENES with the synthetic spectra obtained from the BT-Settl model atmosphere. The detailed spectral synthesis of these observed spectra both in the optical and in the near-infrared helps to understand the missing continuum opacity. Results. For the first time, we derive fundamental stellar parameters of M dwarfs using the high resolution optical and near-infrared spectra simultaneously. We determine Teff, log g and [M/H] for 292 M dwarfs of spectral type M0 to M9, where the formation of dust and clouds are important. The derived Teff for the sample ranges from 2300 to 4000 K, values of log g ranges from 4.5 ≤ logg ≤ 5.5 and the resulting metallicity ranges from −0.5 ≤ [M/H] ≤ +0.5. We have also explored the possible differences in Teff, log g and [M/H] by comparing them with other studies of the same sample of M dwarfs. [ABSTRACT FROM AUTHOR]

Context. Thanks to the importance that the star-planet relation has to our understanding of the planet formation process, the precise determination of stellar parameters for the ever increasing number of discovered extrasolar planets is of great relevance. Furthermore, precise stellar parameters are needed to fully characterize the planet properties. It is thus important to continue the efforts to determine, in the most uniform way possible, the parameters for stars with planets as new discoveries are announced. Aims. In this paper we present new precise atmospheric parameters for a sample of 50 stars with planets. The results are presented in the catalogue: SWEET-Cat. Methods. Stellar atmospheric parameters and masses for the 50 stars were derived assuming local thermodynamic equilibrium and using high-resolution and high signal-to-noise spectra. The methodology used is based on the measurement of equivalent widths with ARES2 for a list of iron lines. The line abundances were derived using MOOG. We then used the curve of growth analysis to determine the parameters. We implemented a new minimization procedure which significantly improves the computational time. Results. The stellar parameters for the 50 stars are presented and compared with previously determined literature values. For SWEETCat, we compile values for the effective temperature, surface gravity, metallicity, and stellar mass for almost all the planet host stars listed in the Extrasolar Planets Encyclopaedia. This data will be updated on a continuous basis. The data can be used for statistical studies of the star-planet correlation, and for the derivation of consistent properties for known planets. [ABSTRACT FROM AUTHOR]

Context. The ever-growing number of large spectroscopic survey programs has increased the importance of fast and reliable methods with which to determine precise stellar parameters. Some of these methods are highly dependent on correct spectroscopic calibrations. Aims. The goal of this work is to obtain a new spectroscopic calibration for a fast estimate of Teff and [Fe/H] for a wide range of stellar spectral types. Methods. We used spectra from a joint sample of 708 stars, compiled from 451 FGK dwarfs and 257 GK-giant stars. We used homogeneously determined spectroscopic stellar parameters to derive temperature calibrations using a set of selected EW line-ratios, and [Fe/H] calibrations using a set of selected Fe I lines. Results. We have derived 322 EW line-ratios and 100 Fe I lines that can be used to compute Teff and [Fe/H], respectively. We show that these calibrations are effective for FGK dwarfs and GK-giant stars in the following ranges: 4500 K < Teff < 6500 K, 2:5 < log g < 4:9 dex, and -0:8 < [Fe/H] < 0:5 dex. The new calibration has a standard deviation of 74 K for Teff and 0:07 dex for [Fe/H].We use four independent samples of stars to test and verify the new calibration, a sample of 56 giant stars, a sample composed of Gaia FGK benchmark stars, a sample of 36 GK-giant stars of the DR1 of the Gaia-ESO survey, and a sample of 582 FGK-dwarf stars. We also provide a new computer code, GeTCal, for automatically producing new calibration files based on any new sample of stars. [ABSTRACT FROM AUTHOR]

Aims. We map the jets and outflows from the Serpens South star-forming region and find an empirical relationship between the magnetic field and outflow orientation. Methods. We performed near-infrared H2 v = 1-0 S(1) 2.122 μm - line imaging of the ∼30' - long filamentary shaped Serpens South star-forming region, and used Ks broadband imaging of the same region for the continuum subraction. Candidate driving sources of the mapped jets/outflows are identified from the list of known protostars and young stars in this region, which was derived from studies using Spitzer and Herschel telescope observations. Results. We identify 14 molecular hydrogen emission-line objects (MHOs) in our continuum-subtracted images. They are found to constitute ten individual flows. Among these, nine flows are located in the lower-half(southern) part of the Serpens South filament, and one flow is located at the northern tip of the filament. Four flows are driven by well-identified Class 0 protostars, while the remaining six flows are driven by candidate protostars mostly in the Class I stage, based on Spitzer and Herschel observations. The orientation of the outflows is systematically perpendicular to the direction of the near-infrared polarization vector published in the literature. No significant correlation was observed between the orientation of the flows and the axis of the filamentary cloud. [ABSTRACT FROM AUTHOR]