Resultados de investigación

The diffuse Fe XXV (6.7keV) line emission observed in the Galactic ridge is widely accepted to be produced by a superposition of a large number of unresolved X-ray point sources. In the very central degrees of our Galaxy, however, the existence of an extremely hot ~7keV diffuse plasma is still under debate. In this work we measure the Fe~XXV line emission using all available XMM-Newton observations of the Galactic centre (GC) and inner disc (-10deg, All XMM-Newton observations covering the GC and inner disc except those already presented in Ponti et al. (2015MNRAS.453..172P). We report the OBSID number, the total and clean exposure time for each camera (in seconds), as well as the custom cut-offs (in counts per second) used for the background filtering after visual inspection of the background light curves. For observations where the threshold column is empty, the standard values of 2.5ct/s and 8.0ct/s for the EPIC MOS and EPIC pn exposures were used respectively., Financial support from the Severo Ochoa grant CEX2021-001131-S funded by MCIN/AEI/ 10.13039/501100011033, No

Detecting a planetary companion in a short-period orbit through radio emission from the interaction with its host star is a new prospect in exoplanet science. A tantalising signal was found by Vedantham et al. (2020NatAs...4..577V) close to the low-mass stellar system GJ 1151 using LOFAR observations. We studied spectroscopic time-series data of GJ 1151 to search for planetary companions and to investigate possible signatures of stellar magnetic activity and to find possible explanations for the radio signal. We used the combined radial velocities measured from spectra acquired with the CARMENES, HARPS-N, and HPF instruments, extracted activity indices from those spectra in order to mitigate the impact of stellar magnetic activity on the data, and analysed in detail Gaia astrometry, and all available photometric time series coming from the MEarth and ASAS-SN surveys. We found a M>10.6M_Earth_ companion to GJ 1151 in a 390-d orbit at a separation of 0.57au. Evidence for a second modulation is also present and could be due to long-term magnetic variability, or a second (substellar) companion. The star shows episodes of elevated magnetic activity, one of which could be linked to the observed LOFAR radio emission. We show that it is highly unlikely that the detected GJ 1151 b, or any additional outer companion can be the source of the detected signal. We cannot firmly rule out the explanation given by Vedantham et al. (2020NatAs...4..577V), as we establish an upper limit of 1.2M_Earth_ for the minimum mass of an undetected short-period planet that could be related to the radio emission., HARPS-N and CARMENES spectroscopic observations of GJ 1151., Financial support from the Severo Ochoa grant CEX2021-001131-S funded by MCIN/AEI/ 10.13039/501100011033, No

We report the discovery of two exoplanets around the M dwarfs GJ 724 and GJ 3988 using the radial velocity (RV) method. We obtained a total of 153 3.5m Calar Alto/CARMENES spectra for both targets and measured their RVs and activity indicators. We also added archival ESO/HARPS data for GJ 724 and infrared RV measurements from Subaru/IRD for GJ 3988. We searched for periodic and stable signals to subsequently construct Keplerian models, considering different numbers of planets, and we selected the best models based on their Bayesian evidence. Gaussian process (GP) regression was included in some models to account for activity signals. For both systems, the best model corresponds to one single planet. The minimum masses are 10.75^+0.96^_-0.87_ and 3.69^+0.42^_-0.41^ Earth-masses for GJ 724 b and GJ 3988 b, respectively. Both planets have short periods (P<10d) and, therefore, they orbit their star closely (a<0.05au). GJ 724 b has an eccentric orbit (e=0.577^+0.055^_-0.052_), whereas the orbit of GJ 3988 b is circular. The high eccentricity of GJ 724 b makes it the most eccentric single exoplanet (to this date) around an M dwarf. Thus, we suggest a further analysis to understand its configuration in the context of planetary formation and architecture. In contrast, GJ 3988 b is an example of a common type of planet around mid-M dwarfs., The spectral data were obtained with CARMENES for both GJ 724 and GJ 3988. We also incorporated RV data from the High Accuracy Radial velocity Planet Searcher spectrograph (HARPS) for GJ 724. For GJ 3988, we used data from the InfraRed Doppler (IRD) at the Subaru Telescope. We discovered GJ 724 b and GJ 3988 b using RV measurements from CARMENES, HARPS, and IRD. We measured the mean stellar rotation periods for both stars using photometric data, obtaining 116+/-2d for GJ 3988, and 57+/-1d for GJ 724, although we cannot completely exclude its second harmonic (~28d) as a possible rotation period., Financial support from the Severo Ochoa grant CEX2021-001131-S funded by MCIN/AEI/ 10.13039/501100011033, No

The Carina Nebula is one of the major massive star-forming regions in the Galaxy. Its relatively nearby distance (2.35kpc) makes it an ideal laboratory for the study of massive star formation, structure and evolution both for individual stars and stellar systems. Thanks to the high-quality spectra provided by the Gaia-ESO survey and the LiLiMaRlin library, as well as Gaia EDR3 astrometry, a detailed and homogeneous spectroscopic characterization of its massive stellar content can be carried out. Our main objective is to spectroscopically characterize all massive members of the Carina Nebula in the Gaia-ESO survey footprint to provide an updated census of massive stars in the region and an updated estimate of the binary fraction of O stars. We performed accurate spectral classification using an interactive code that compares spectra with spectral libraries of OB standard stars, as well as line-based classic methods. We calculated membership using our own algorithm based on Gaia EDR3 astrometry. To check the correlation between the spectroscopic n-qualifier and the rotational velocity, we used a semi automated tool for the line-broadening characterization of OB stars based on a combined Fourier transform and goodness-of-fit methodology. The Gaia-ESO survey sample of massive OB stars in the Carina Nebula consists of 234 stars. The addition of brighter sources from the Galactic O-Star Spectroscopic Survey and additional sources from the literature allows us to create the most complete census of massive OB stars done so far in the region. It contains a total of 316 stars, with 18 of them in the background and 4 in the foreground. Of the 294 stellar systems in Car OB1, 74 are of O type, 214 are of non-supergiant B type and 6 are of WR or non-O supergiant (II to Ia) spectral class. We identify 20 spectroscopic binary systems with an O-star primary, of which 6 are reported for the first time, and another 18 with a B-star primary, of which 13 are new detections. The average observed double-lined binary fraction of O-type stars in the surveyed region is 0.35, which represents a lower limit. We find a good correlation between the spectroscopic n-qualifier and the projected rotational velocity of the stars. The fraction of candidate runaways among the stars with and without the n-qualifier is 4.4% and 2.4%, respectively, although non resolved double-lined binaries could be contaminating the sample of fast rotators., New census of massive stars in the central region of the Carina Nebula that contains 316 stars. Massive OB stars include all O-types and those B2-types or earlier for dwarfs, B5-types or earlier for giants, and all B subtypes for supergiants (I or II luminosity classes). Red supergiants (RSGs), Wolf-Rayet (WR) stars, and some B subtypes close to the OB-star limit (e.g. B2.5 V) are also included in the census for completeness. Stars are separated assuming distances compatible with Car OB1 from those in the foreground and background., Financial support from the Severo Ochoa grant CEX2021-001131-S funded by MCIN/AEI/ 10.13039/501100011033, No

Galactic winds play a key role in regulating the evolution of galaxies over cosmic time. In recent years, the role of cosmic rays (CRs) in the formation of the galactic wind has increasingly gained attention. Therefore, we use radio continuum data to analyse the CR transport in edge-on galaxies. With newly reduced radio continuum data of five edge-on galaxies (NGC 891, NGC 3432, NGC 4013, NGC 4157, and NGC 4631), we plan to set new constraints on the morphology of radio halos and the physical properties of galactic winds driven by stellar feedback. By distinguishing between the central and outer regions of the galaxies, our study setup allows us to search for variations in the radio halo profile or CR transport along the galactic disk. Data from the LOFAR Two-metre Sky Survey (LoTSS) Data Release 2 at 144MHz (HBA) and reprocessed data from the Very Large Array (VLA) at 1.5GHz (L band) from the Continuum Halos in Nearby Galaxies -- an EVLA Survey (CHANG-ES) enable us to increase the extent of the analysed radio continuum profile significantly (up to a factor of 2) compared to previous studies. We computed thermal emission maps using a mixture approach with H-alpha and near-infrared data, which were then subtracted to yield radio synchrotron emission maps. Then we compiled non-thermal spectral index maps and computed intensity profiles using a box integration approach. Lastly, we performed 1D CR transport modelling. The non-thermal spectral index maps show evidence that the LoTSS maps are affected by thermal absorption in star-forming regions. The scale height analysis reveals that most of the galaxies are equally well fitted with a one-component instead of a two component exponential profile. We find a bi-modality within our sample. While NGC 3432 and NGC 4013 have similar scale heights in the L band and HBA, the low-frequency scale heights of NGC 891, NGC 4157, and NGC 4631 exceed their high-frequency counterpart significantly. The 1D CR transport modelling shows agreement between the predicted magnetic field strength and the magnetic field strength estimates of equipartition measurements. Additionally, we find an increasing difference in wind velocities (with increasing height over the galactic disk) between the central and outer regions of the analysed galaxies., Here, we provide the VLA L band (C- and D-configuration combined) maps of the five galaxies that have bin analysed in this paper after point source subtraction and masking as well as the non-thermal spectral index maps between LOFAR HBA (144MHz) and L band (1.5GHz). We corrected for thermal emission in the L band data. The calibration strategy of the D-Array data is described in Wiegert et al., 2015AJ....150...81W., Financial support from the Severo Ochoa grant CEX2021-001131-S funded by MCIN/AEI/ 10.13039/501100011033, No

The CARMENES instrument, installed at the 3.5-m telescope of the Calar Alto observatory in Almeria, Spain, was conceived to deliver high-accuracy radial velocity (RV) measurements with long-term stability to search for temperate rocky planets around a sample of nearby cool stars. Moreover, the broad wavelength coverage was designed to provide a range of stellar activity indicators to assess the nature of potential RV signals and also valuable spectral information to characterise the stellar targets. Here, we describe the CARMENES Guaranteed Time Observations (GTO), which ran from 2016 to 2020 and collected 19633 spectra for a sample of 362 targets. We present the CARMENES Data Release 1 (DR1), which makes public all observations obtained during the GTO of the CARMENES survey. The CARMENES survey target selection was aimed at minimising biases and about 70% of all known M dwarfs within 10 pc accessible from Calar Alto were included. The data are pipeline-processed and high-level data products, including 18642 precise RVs for 345 targets, are derived. Time series data of spectroscopic activity indicators are also obtained. We discuss the characteristics of CARMENES data and the statistical properties of the stellar sample and the spectroscopic measurements. We show examples of the use of CARMENES data and provide a contextual view of the exoplanet population revealed by the survey, including 33 new planets, 17 reanalysed planets, and 26 confirmed planets from transiting candidate follow-up. A subsample of 238 targets is used to derive updated planet occurrence rates, yielding an overall average of 1.44+/-0.20 planets with 1M_{Earth}_, In Table 1, we provide the the list of stars of the CARMENES GTO survey included in the data release DR1. Star identifier, the number of radial velocity measurements and spectra, the mass, the radius, the effective temperature, and the rotation period (if known) of each star are listed. The nightly zero point radial velocity average value used to correct data from instrumental systematics are given in Table 2. The radial velocity correction, its uncertainty, the number of measurements averaged, and a quality flag are provided for each night., Financial support from the Severo Ochoa grant CEX2021-001131-S funded by MCIN/AEI/ 10.13039/501100011033, No

We present the detection of 68 sources from the most sensitive radio survey in circular polarisation conducted to date. We used the second data release of the 144MHz LOFAR Two-metre Sky Survey to prodce circularly polarised maps with a median noise of 140uJy/beam and resolution of 20-arcsec for 27% of the northern sky (5634deg^2^). The leakage of total intensity into circular polarisation is measured to be ~0.06%, and our survey is complete at flux densities >=1mJy. A detection is considered reliable when the circularly polarised fraction exceeds 1%. We find the population of circularly polarised sources is composed of four distinct classes: stellar systems, pulsars, active galactic nuclei, and sources unidentified in the literature. The stellar systems can be further separated into chromospherically active stars, M dwarfs, and brown dwarfs. Based on the circularly polarised fraction and lack of an optical counterpart, we show it is possible to infer whether the unidentified sources are likely unknown pulsars or brown dwarfs. By the completion of this survey of the northern sky, we expect to detect 300+/-100 circularly polarised sources., The column numbers, names, and units for the V-LoTSS catalogue are described below. All Stokes I information is similar to that found in the LoTSS-DR2 catalogue but can differ depending on whether the source is variable (Shimwell et al., 2022A&A...659A...1S, Cat. J/A+A/659/A1). For the few sources that are not present in LoTSS-DR2 because of their variability, we have formed their LoTSS name in line with the convention defined by (Shimwell et al., 2022A&A...659A...1S, Cat. J/A+A/659/A1). We report some Gaia DR3 measurements if the Stokes V source has a counterpart in that survey. Similarly, we report some pulsar properties if the source has a counterpart in Australia Telescope National Facility Pulsar Catalogue (PSRCAT; v1.68; Manchester et al., 2005AJ....129.1993M, Cat. B/psr). Full details can be found in the paper., Financial support from the Severo Ochoa grant CEX2021-001131-S funded by MCIN/AEI/ 10.13039/501100011033, No

We present the discovery of an Earth-mass planet (M_b_sini=1.36+/-0.21M_{Earth}_) on a 15.6d orbit of a relatively nearby (d~9.6pc) and low-mass (0.167+/-0.011M_{sun}_) M5.0V star, Wolf 1069. Sitting at a separation of 0.0672+/-0.0014au away from the host star puts Wolf 1069b in the habitable zone (HZ), receiving an incident flux of S=0.652+/-0.029S_{Earth}_. The planetary signal was detected using telluric-corrected radial-velocity (RV) data from the CARMENES spectrograph, amounting to a total of 262 spectroscopic observations covering almost four years. There are additional long-period signals in the RVs, one of which we attribute to the stellar rotation period. This is possible thanks to our photometric analysis including new, well-sampled monitoring campaigns undergone with the OSN and TJO facilities that supplement archival photometry (i.e., from MEarth and SuperWASP), and this yielded an updated rotational period range of P_rot_=150-170d, with a likely value at 169.3^+3.7^_-3.6_d. The stellar activity indicators provided by the CARMENES spectra likewise demonstrate evidence for the slow rotation period, though not as accurately due to possible factors such as signal aliasing or spot evolution. Our detectability limits indicate that additional planets more massive than one Earth mass with orbital periods of less than 10 days can be ruled out, suggesting that perhaps Wolf 1069b had a violent formation history. This planet is also the 6th closest Earth-mass planet situated in the conservative HZ, after Proxima Centauri b, GJ 1061d, Teegarden's Star c, and GJ 1002 b and c. Despite not transiting, Wolf 1069b is nonetheless a very promising target for future three-dimensional climate models to investigate various habitability cases as well as for sub-m/s RV campaigns to search for potential inner sub-Earth-mass planets in order to test planet formation theories., CARMENES VIS radial-velocity and stellar activity indicator time series of Wolf 1069. These were all processed with serval (Zechmeister et al., 2018A&A...609A..12Z). Photometric time series for Wolf 1069 with the following facilities: SuperWASP, MEarth, OSN, TJO, Financial support from the Severo Ochoa grant CEX2021-001131-S funded by MCIN/AEI/ 10.13039/501100011033, No

The environments where galaxies reside affects their evolutionary histories. Galaxy triplets (systems composed of three physically bound galaxies) are one of simplest groups of galaxies, and are therefore excellent laboratories to study evolutionary mechanisms where effects of the environment are minimal. We present a statistical study of the dynamical properties of isolated galaxy triplets as a function of their local and large-scale environments. To explore the connection of the dynamical evolution on the systems with the evolution of the galaxies composing the triplets, we consider observational properties such as morphology and star formation rate (SFR). We used the SDSS-based catalogue of Isolated Triplets (SIT), which contains 315 triplets. We classified each triplet according to galaxy morphologies and defined a parameter Qtrip to quantify the total local tidal strengths in the systems. To quantify the dynamical stage of the system we used the parameters of harmonic radius RH , velocity dispersion {sigma}_vr_, crossing time H_0_t_c_, and virial mass M_vir_. Triplets composed of three early-type galaxies present the smallest R_H_, indicating that they are in general more compact than triplets with one or more late-type galaxies. Among triplets with low values of R_H_ and H_0_t_c_, SIT triplets with Q_trip_<-2 are relaxed systems that are more dynamically evolved, while triplets with Q_trip_>-2 show compact configurations due to interactions within the system, such as ongoing mergers. We found that there is no dominant galaxy in triplets in terms of properties of stellar populations such as global colour and SFR. Moreover, the global SFR in isolated triplets composed of two or more early-type galaxies increases with the stellar mass ratio of the galaxies with respect to the central galaxy, therefore the system is globally 'rejuvenated'., Dynamical parameters (harmonic radius, velocity dispersion, crossing time, and virial mass), total local tidal strength (Q_trip_), and morphology categories for the 315 triplets in the SIT., Financial support from the Severo Ochoa grant CEX2021-001131-S funded by MCIN/AEI/ 10.13039/501100011033, No

"Cybele asteroids constitute an appealing reservoir of primitive material genetically linked to the outer Solar System, and the physical properties (size and shape) of the largest members can be readily accessed by large (8m class) telescopes. We took advantage of the bright apparition of the most iconic member of the Cybele population, (65) Cybele, in July and August 2021 to acquire high-angular-resolution images and optical light curves of the asteroid with which we aim to analyse its shape and bulk properties. Eight series of images were acquired with VLT/SPHERE+ZIMPOL, seven of which were combined with optical light curves to reconstruct the shape of the asteroid using the ADAM, MPCD, and SAGE algorithms. The origin of the shape was investigated by means of N-body simulations. Cybele has a volume-equivalent diameter of 263+/-3km and a bulk density of 1.55+/-0.19g/cm^3^. Notably, its shape and rotation state are closely compatible with those of a Maclaurin equilibrium figure. The lack of a collisional family associated with Cybele and the higher bulk density of that body with respect to other large P-type asteroids suggest that it never experienced any large disruptive impact followed by rapid re-accumulation. This would imply that its present-day shape represents the original one. However, numerical integration of the long-term dynamical evolution of a hypothetical family of Cybele shows that it is dispersed by gravitational perturbations and chaotic diffusion over gigayears of evolution. The very close match between Cybele and an equilibrium figure opens up the possibility that D>=260km (M>=1.5x10^19^kg) small bodies from the outer Solar System all formed at equilibrium. However, we cannot currently rule out an old impact as the origin of the equilibrium shape of Cybele. Cybele itself is found to be dynamically unstable, implying that it was ""recently"" (<1Gyr ago) placed on its current orbit either through slow diffusion from a relatively stable orbit in the Cybele region or, less likely, from an unstable, Jupiter-family-comet orbit in the planet-crossing region.", We obtained 70 images of Cybele at 7 epochs in 2021 using VLT/SPHERE/ZIMPOL. All images were reduced and deconvolved following the procedure described in Vernazza et al. (2018A&A...618A.154V). objects: ---------------------------------------------------------------- Planet Name H Diam i e a mag km deg AU ------------------------------------------------------------------- 65 Cybele 6.92 263 3.567994 0.116080 3.4390432 -------------------------------------------------------------------, Financial support from the Severo Ochoa grant CEX2021-001131-S funded by MCIN/AEI/ 10.13039/501100011033, No