Resultados de investigación

The local radio-loud AGN population is dominated by compact sources named FR0s. These sources show features, for example the host type, the mass of the supermassive black hole (SMBH), and the multi-band nuclear characteristics, that are similar to those of FRI radio galaxies. However, in the radio band, while FR0 and FRI share the same nuclear properties, the kiloparsec-scale diffuse component dominant in FRI is missing in FR0s. Previous very-long-baseline interferometry (VLBI) observations of a small sample of FR0s show a complex structure, mostly symmetric (two-sided jets) with respect to the central core. With this project we would like to study the parsec-scale structure in FR0s in comparison with that of FRI sources. Jets in FRI are relativistic on the parsec scale and decrease their velocity becoming subrelativistic on the kiloparsec scale. We would like to test whether this result also applies to the jets in FR0s or, alternatively, whether they are subrelativistic on the parsec scale. This might be the reason why they are unable to grow, because of instabilities, related to a low jet bulk velocity. To this end we observed 18 FR0 galaxies with the VLBA at 1.5 and 5GHz and/or with the EVN at 1.7GHz and produced detailed images at milliarcsec resolution of their nuclear emission to study the jet and core structure. All sources have been detected but one. Four sources are unresolved, even in these high-resolution images; jets have been detected in all other sources. We derived the distribution of the jet-to-counter-jet ratio of FR0s and found that it is significantly different from that of FRIs, suggesting different jet bulk speed velocities. Conclusions. Combining the present data with published data of FR0 with VLBI observations, we derive that the radio structure of FR0 galaxies shows strong evidence that parsec-scale jets in FR0 sources are mildly relativistic with a bulk velocity on the order of 0.5c or less. A jet structure with a thin inner relativistic spine surrounded by a low-velocity sheath could be in agreement with the SMBH and jet launch region properties, Among the 25 FR0s studied with JVLA observations in the A array (Baldi et al. 2015A&A...576A..38B, 2019MNRAS.482.2294B), we selected sources with a core flux density at 1.4GHz greater than 20 mJy and z<0.05. The 11 sources selected were observed with EVN at 1.7GHz. Observations were carried in May 2019 in phase reference mode with a data rate of 1024 Mbit/sec (project EG100). Nearby phase calibrators selected from the VLBA calibrator list, and target sources were observed with a ~5min cycle. The total observing time was ~2hr/source with at least 60 min on the target source and the remaining time on calibrator source and motion. Moreover, in the time range September - December 2021 we observed 11 FR0s with the VLBA at 5 and 1.5GHz (project BG272). Selected, Financial support from the Severo Ochoa grant CEX2021-001131-S funded by MCIN/AEI/ 10.13039/501100011033, No

NASA's Transiting Exoplanet Survey Satellite (TESS) mission promises to improve our understanding of hot Jupiters by providing an all-sky, magnitude-limited sample of transiting hot Jupiters suitable for population studies. Assembling such a sample requires confirming hundreds of planet candidates with additional follow-up observations. Here we present 20 hot Jupiters that were detected using TESS data and confirmed to be planets through photometric, spectroscopic, and imaging observations coordinated by the TESS Follow-up Observing Program. These 20 planets have orbital periods shorter than 7 days and orbit relatively bright FGK stars (10.9, The 20 planets described in this paper were first identified as transiting planet candidates in the TESS photometry. Following the conclusion of its Prime Mission in July 2020, TESS reobserved most of the sky as part of the first Extended Mission (EM1). Six of our targets (TOI-1937b, -2583b, -3807b, -3819b, -3912b, and -4087b) were identified as planet candidates based on Prime Mission data and selected for 2 minute cadence observations during EM1. The remaining objects continued to be observed as part of the FFIs, which are available with a 10 minute cadence in EM1. See Section 2.1. Two of our targets, TOI-2583b and TOI-2803b, were also detected as planet candidates by the WASP transit search (Pollacco+ 2006PASP..118.1407P). The WASP survey comprises two wide-field camera arrays at the Observatorio del Roque de los Muchachos on La Palma and the Sutherland Station of the South African Astronomical Observatory (SAAO). TOI-2583 was observed by WASP between 2004 and 2010, while TOI-2803 was observed between 2006 and 2012, with the transit events detected at the same period as those found by TESS. In addition to TOI-2583 and TOI-2803, archival WASP photometry was also available for TOI-2587, TOI-3364, TOI-3819, TOI-3912, and TOI-3976. See Section 2.2. Apart from the TESS and archival WASP photometry, we obtained additional light curves from a wide range of ground-based facilities, organized by the TFOP Seeing-limited Photometry Sub-Group 1. We summarize all the ground-based follow-up photometry in Table 3. See Section 2.3. As part of follow-up observations coordinated by the TFOP High-Resolution Imaging Sub-Group 3 (SG3), we obtained high angular-resolution imaging of all the targets described here. Observations, spanning 2020-Mar-13 to 2022-May-21 were made using several telescopes. These imaging observations are summarized in Table 4. See Section 2.4. In order to confirm each planetary candidate and measure its mass, we obtained high-resolution spectroscopy of their host stars. These observations (spanning 2006-Oct-20 to 2022-Aug-23) are summarized in Table 5. See Section 2.5. To ensure we have a complete view of each planetary system, we gather information about each target from the literature. We obtained photometric and astrometric observations from the TESS Input Catalog (TIC; see IV/38 and IV/39), Gaia DR3 (see I/355), 2MASS (see II/246), WISE (see II/311), and Tycho-2 (see I/259) catalogs. See Section 2.6. Finally, we observed a transit of TOI-1937Ab on the night of 2020-December-29 both spectroscopically and photometrically, in order to measure the projected stellar obliquity through the Rossiter-McLaughlin effect. The photometric observations were acquired from El Sauce, and the spectroscopy was acquired using Magellan/PFS. The photometric results are shown in Figure 15, with the transit occurring at the expected time. See Section 2.7., Financial support from the Severo Ochoa grant CEX2021-001131-S funded by MCIN/AEI/ 10.13039/501100011033, No

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