Resultados de investigación

Hickson compact groups (HCGs) are dense configurations of four to ten galaxies, whose HI morphology appears to follow an evolutionary sequence of three phases, with gas initially confined to galaxies, then significant amounts spread throughout the intra-group medium, and finally with almost no gas remaining in the galaxies themselves. It has also been suggested that several groups may harbour a diffuse HI component that is resolved out by interferometric observations. The HI deficiency of HCGs is expected to increase as the HI morphological phase progresses along the evolutionary sequence. If this is the case, HI deficiency would be a rough proxy for the age and evolutionary state of a HCG. We aim to test this hypothesis for the first time using a large sample of HCGs and to investigate the evidence for diffuse HI in HCGs. We performed a uniform reduction of all publicly available VLA HI observations (38 HCGs) with a purpose-built pipeline that also maximises the reproducibility of this study. The resulting HI data cubes were then analysed with the latest software tools to perform a manual separation of emission features into those belonging to galaxies and those extending into the intra-group medium. We thereby classified the HI morphological phase of each group as well as quantified their HI deficiency compared to galaxies in isolation. We find little evidence that HI deficiency can be used as a proxy for the evolutionary phase of a compact group in either of the first two phases, with the distribution of HI deficiency being consistent in both. However, for the final phase, the distribution clearly shifts to high HI deficiencies, with more than 90% of the expected HI content typically missing. Across all HCGs studied, we identify a few cases where there is strong evidence for a diffuse gas component in the intra-group medium, which might be detectable with improved observations. We also classify a new sub-phase where groups contain a lone HI-bearing galaxy, but are otherwise devoid of gas. The new morphological phase we have identified is likely the result of an evolved, gas-poor group acquiring a new, gas-rich member. The large spread of HI deficiencies in the first two morphological phases suggests that there is a broad range of initial HI content in HCGs, which is perhaps influenced by large-scale environment, and that the timescale for morphological changes is, in general, considerably shorter than the timescale for the destruction or consumption of neutral gas in these systems., Here we present the tables of HI measurements from the paper., Financial support from the Severo Ochoa grant CEX2021-001131-S funded by MCIN/AEI/ 10.13039/501100011033, No

We report the discovery and characterisation of two Earth-mass planets orbiting in the habitable zone of the nearby M-dwarf GJ 1002 based on the analysis of the radial-velocity (RV) time series from the ESPRESSO and CARMENES spectrographs. The host star is the quiet M5.5 V star GJ 1002 (relatively faint in the optical, V~13.8mag, but brighter in the infrared, J~8.3mag), located at 4.84pc from the Sun. We analyse 139 spectroscopic observations taken between 2017 and 2021. We performed a joint analysis of the time series of the RV and full-width half maximum (FWHM) of the cross-correlation function (CCF) to model the planetary and stellar signals present in the data, applying Gaussian process regression to deal with the stellar activity. We detect the signal of two planets orbiting GJ 1002. GJ 1002 b is a planet with a minimum mass m_p_sini of 1.08+/-0.13M_{sun}_ with an orbital period of 10.3465+/-0.0027 days at a distance of 0.0457+/-0.0013au from its parent star, receiving an estimated stellar flux of 0.67F_{sun}_. GJ 1002 c is a planet with a minimum mass m_p_sini of 1.36+/-0.17M_{sun}_ with an orbital period of 20.202+/-0.013 days at a distance of 0.0738+/-0.0021au from its parent star, receiving an estimated stellar flux of 0.257F_{sun}_. We also detect the rotation signature of the star, with a period of 126+/-15 days. We find that there is a correlation between the temperature of certain optical elements in the spectrographs and changes in the instrumental profile that can affect the scientific data, showing a seasonal behaviour that creates spurious signals at periods longer than ~200 days. GJ 1002 is one of the few known nearby systems with planets that could potentially host habitable environments. The closeness of the host star to the Sun makes the angular sizes of the orbits of both planets (~9.7 mas and ~15.7mas, respectively) large enough for their atmosphere to be studied via high-contrast high-resolution spectroscopy with instruments such as the future spectrograph ANDES for the ELT or the LIFE mission., Radial velocity, FWHM and echelle temperature data of the observations of GJ 1002 with ESPRESSO and CARMENES., Financial support from the Severo Ochoa grant CEX2021-001131-S funded by MCIN/AEI/ 10.13039/501100011033, No

The rotational states of the members in the dwarf planet - satellite systems in the transneptunian region are determined by the formation conditions and the tidal interaction between the components, and these rotational characteristics are the prime tracers of their evolution. Previously a number of authors claimed highly diverse values for the rotation period for the dwarf planet Eris, ranging from a few hours to a rotation (nearly) synchronous with the orbital period (15.8d) of its satellite, Dysnomia. In this letter we present new light curve data of Eris, taken with ~1-2m-class ground based telescopes, and with the TESS and Gaia space telescopes. TESS data could not provide a well-defined light curve period, but could constrain light curve variations to a maximum possible light curve amplitude of dm<=0.03mag (1-sigma) for P<=24h periods. Both the combined ground-based data and the Gaia measurements unambiguously point to a light curve period equal to the orbital period of Dysnomia, P=15.8d, with a light curve amplitude of dm~0.03mag, i.e. the rotation of Eris is tidally locked. Assuming that Dysnomia has a collisional origin, calculations with a simple tidal evolution model show that Dysnomia has to be relatively massive (mass ratio of q=0.01-0.03) and large (radius of R_s_>=300km) to slow down Eris to synchronized rotation. These simulations also indicate that - assuming tidal parameters usually considered for transneptunian objects - the density of Dysnomia should be 1.8-2.4g/cm^3^, an exceptionally high value among similarly sized transneptunian objects, putting important constraints on the formation conditions., Collected photometry data from Gaia space observatory, TESS and from ground based telescopes, e.g. MPG 2.2m (GROND), La Hita 0.77m, CA2.2 (CAFOS2.2) and 1.5m telescope at Observatorio de Sierra Nevada., Financial support from the Severo Ochoa grant CEX2021-001131-S funded by MCIN/AEI/ 10.13039/501100011033, No

We report the first results of a high-redshift (z>~5) quasar survey using the Dark Energy Spectroscopic Instrument (DESI). As a DESI secondary target program, this survey is designed to carry out a systematic search and investigation of quasars at 4.8=5, more than one-third of existing quasars previously published at this redshift. The observations so far result in an average success rate of 23% at z>4.7. The current spectral data set has already allowed analysis of interesting individual objects (e.g., quasars with damped Ly{alpha} absorbers and broad absorption line features), and statistical analysis will follow the survey's completion. A set of science projects will be carried out leveraging this program, including quasar luminosity function, quasar clustering, intergalactic medium, quasar spectral properties, intervening absorbers, and properties of early supermassive black holes. Additionally, a sample of 38 new quasars at z~3.8-5.7 discovered from a pilot survey in the DESI SV1 is also published in this paper., The selected z~4.8-6.8 quasar candidates are mainly observed as dark-time targets in the Dark Energy Spectroscopic Instrument (DESI) main survey, which started on 2021-May-14. A minor part (1.6%) of candidates were observed during the DESI 1% survey (SV3; in 2021 April) and the DESI SV1 (before 2021 April 4; for 27 targets overlapped with the SV1 selection)., Financial support from the Severo Ochoa grant CEX2021-001131-S funded by MCIN/AEI/ 10.13039/501100011033, No

The current architecture of a given multi-planetary system is a key fingerprint of its past formation and dynamical evolution history. Long-term follow-up observations are key to complete their picture. In this paper we focus on the confirmation and characterization of the components of the TOI-969 planetary system, where TESS detected a Neptune-size planet candidate in a very close-in orbit around a late K-dwarf star. We use a set of precise radial velocity observations from HARPS, PFS and CORALIE instruments covering more than two years in combination with the TESS photometric light curve and other ground-based follow-up observations to confirm and characterize the components of this planetary system. We find that TOI-969 b is a transiting close-in (Pb~1.82days) mini-Neptune planet (m_b_=9.1^+1.1^_1.0_M_{Earth}_, R_b_=2.765^+0.088^_0.097_R_{Earth}_), thus placing it on the {lower boundary} of the hot-Neptune desert (T_eq,b_=941+/-31K). The analysis of its internal structure shows that TOI-969 b is a volatile-rich planet, suggesting it underwent an inward migration. The radial velocity model also favors the presence of a second massive body in the system, TOI-969 c, with a long period of P_c_=1700^+290^_280_days and a minimum mass of m_c_sini_c_=11.3^+1.1^_0.9_M_Jup_, and with a highly-eccentric orbit of e_c_=0.628^+0.043^_0.036_. The TOI-969 planetary system is one of the few around K-dwarfs known to have this extended configuration going from a very close-in planet to a wide-separation gaseous giant. TOI-969 b has a transmission spectroscopy metric of 93, and it orbits a moderately bright (G=11.3mag) star, thus becoming an excellent target for atmospheric studies. The architecture of this planetary system can also provide valuable information about migration and formation of planetary systems., Detection and characterization of the planet TOI-969b and its external long-period planetary-mass companion with radial velocity, high-spatial resolution imaging and high-precision photometry., Financial support from the Severo Ochoa grant CEX2021-001131-S funded by MCIN/AEI/ 10.13039/501100011033, No

The 4D Eigenvector 1 empirical formalism (4DE1) and its main sequence (MS) for quasars has emerged as a powerful tool for organising the diversity among quasar populations, as several key observational measures and physical parameters are systematically changing along it. Trends revealed by 4DE1 are very well established to explain all the diverse characteristics seen in low-redshift quasar samples. Nevertheless, the situation is far less clear when dealing with high-luminosity and high-redshift sources. Here, we aim to evaluate the behaviour of our sample of 22 quasars at high redshift (2.2<=z<=3.7) and high luminosity (47.39<=L_bol_<=48.36) in the context of the 4DE1. Our approach involves studying quasar physics through a spectroscopic exploration of UV and optical emission line diagnostics. We used new observations from the ISAAC instrument at ESO-VLT and primarily from the SDSS to cover the optical and the UV rest-frames, respectively. The emission lines were characterised both via a quantitative parametrisation of the line profiles and a decomposition of the emission line profiles using multicomponent fitting routines. We provide spectrophotometric properties and line profile measurements for H{beta}+[OIII]4959,5007, as well as SiIV1397+OIV]1402, CIV1549+HeII1640, and the 1900{AA} blend (including AlIII1860, SiIII]1892, and CIII]1909). For six out of the 22 objects, a significantly blueshifted component on the H{beta} profile is present. In 14 out of 22 cases, an H{beta} outflowing component associated with [OIII] is detected. The majority of [OIII]4959,5007 emission line profiles show blueshifted velocities higher than 250km/s. We find extremely broad [OIII]4959,5007 emission that is comparable to the width of H{beta} broad profile in some highly accreting quasars. The [OIII]4959,5007 and CIV1549 blueshifts show very high amplitudes and a high degree of correlation. The line widths and shifts are correlated for both [OIII]4959,5007 and CIV1549, suggesting that emission from outflowing gas is providing a substantial broadening effect to both lines. Otherwise, the links between CIV1549 centroid velocity at half intensity (c(1/2)), Eddington ratio (L/L_Edd_), and bolometric luminosity are found to be in agreement with previous studies of high-luminosity quasars. Our analysis suggests that the behaviour of quasars of very high luminosity all along the main sequence is strongly affected by powerful outflows involving a broad range of spatial scales. The main sequence correlations remain valid at high redshift and high luminosity even if a systematic increase in line width is observed. Scaling laws based on UV AlIII1860 and H{beta} emission lines are equally reliable estimators of M_BH_., Our sample consists of 22 quasars with high redshift, going from z=2.2 to z=3.7, and with high luminosity (47.39<=logLbol<=48.36[erg/s]), including both radio-loud and radio-quiet sources that were observed under the ESO programmes 083.B-0273(A) and 085.B-0162(A). Our sample covers a redshift that allows for the detection and observation of the H{alpha}+[OIII]4959,5007 region through the transparent window in the near-infrared with the ISAAC spectrograph at VLT (Sulentic et al., 2006A&A...456..929S, 2017A&A...608A.122S, Cat. J/A+A/608/A122). Table 1 presents the main properties of our sample. Spectra were taken in service mode in 2009 and 2010, with the infrared spectrometer ISAAC, mounted at the Nasmyth B focus of VLT-U1 (Antu) until August 2009, and later at the Nasmyth A focus of VLT-U3 (Melipal) at the ESO Paranal Observatory., Financial support from the Severo Ochoa grant CEX2021-001131-S funded by MCIN/AEI/ 10.13039/501100011033, No

We present results from wide-field imaging of the resolved stellar populations of the dwarf spheroidal galaxies CassiopeiaIII (AndXXXII) and PerseusI (AndXXXIII), two satellites in the outer stellar halo of the Andromeda galaxy (M31). Our WIYN pODI photometry traces the red giant star population in each galaxy to ~2.5-3 half-light radii from the galaxy center. We use the tip of the red giant branch (TRGB) method to derive distances of (m-M)0=24.62{+/-}0.12mag (839_-45_^+48^kpc, or 156_-13_^+16^kpc from M31) for CasIII and 24.47{+/-}0.13mag (738_-45_^+48^kpc, or 351_-16_^+17^kpc from M31) for Per I. These values are consistent within the errors with TRGB distances derived from a deeper Hubble Space Telescope study of the galaxies inner regions. For each galaxy, we derive structural parameters, total magnitude, and central surface brightness. We also place upper limits on the ratio of neutral hydrogen gas mass to optical luminosity, confirming the gas-poor nature of both galaxies. We combine our data set with corresponding data for the M31 satellite galaxy LacertaI (AndXXXI) from earlier work and search for substructure within the RGB star populations of CasIII, PerI, and Lac I. We find an overdense region on the west side of Lac I at a significance level of 2.5{sigma}-3{sigma} and a low-significance filament extending in the direction of M31. In CasIII, we identify two modestly significant overdensities near the center of the galaxy and another at two half-light radii. PerI shows no evidence for substructure in its RGB star population, which may reflect this galaxy's isolated nature., "Observations of Cas III and Per I were obtained on 2013 October 2-3 and 2013 October 29-31, respectively, with the WIYN 3.5m telescope and the One Degree Imager camera with a partially filled focal plane. The field of view of the central imaging area in pODI was ~24x24', with a pixel scale of 0.11""/pixel. The galaxies were observed in the SDSS g and i filters. Several 600-700s exposures were taken of each galaxy in each filter over the course of the observing run.", Financial support from the Severo Ochoa grant CEX2021-001131-S funded by MCIN/AEI/ 10.13039/501100011033, No

As evidenced by recent survey results, the majority of asteroids are slow rotators (spin periods longer than 12h), but lack spin and shape models because of selection bias. This bias is skewing our overall understanding of the spins, shapes, and sizes of asteroids, as well as of their other properties. Also, diameter determinations for large (>60km) and medium-sized asteroids (between 30 and 60km) often vary by over 30% for multiple reasons. Our long-term project is focused on a few tens of slow rotators with periods of up to 60 h. We aim to obtain their full light curves and reconstruct their spins and shapes. We also precisely scale the models, typically with an accuracy of a few percent. We used wide sets of dense light curves for spin and shape reconstructions via light-curve inversion. Precisely scaling them with thermal data was not possible here because of poor infrared datasets: large bodies tend to saturate in WISE mission detectors. Therefore, we recently also launched a special campaign among stellar occultation observers, both in order to scale these models and to verify the shape solutions, often allowing us to break the mirror pole ambiguity. The presented scheme resulted in shape models for 16 slow rotators, most of them for the first time. Fitting them to chords from stellar occultation timings resolved previous inconsistencies in size determinations. For around half of the targets, this fitting also allowed us to identify a clearly preferred pole solution from the pair of two mirror pole solutions, thus removing the ambiguity inherent to light-curve inversion. We also address the influence of the uncertainty of the shape models on the derived diameters. Overall, our project has already provided reliable models for around 50 slow rotators. Such well-determined and scaled asteroid shapes will, for example, constitute a solid basis for precise density determinations when coupled with mass information. Spin and shape models in general continue to fill the gaps caused by various biases., "The files contain asteroid brightness and geometry for corresponding epochs. The ""*lcs.dat"" files were used for obtaining shape models and spin states of the asteroids using multi-apparition data. Individual lightcurves within a file are separated by an empty line, all lightcurves are relative.", Financial support from the Severo Ochoa grant CEX2021-001131-S funded by MCIN/AEI/ 10.13039/501100011033, No

Hot Jupiters have been perceived as loners devoid of planetary companions in close orbital proximity. However, recent discoveries based on space-borne precise photometry have revealed that at least some fraction of giant planets coexists with low-mass planets in compact orbital architectures. We report detecting a 1.446-d transit-like signal in the photometric time series acquired with the Transiting Exoplanet Survey Satellite (TESS) for the WASP-84 system, which is known to contain a hot Jupiter on a circular 8.5-d orbit. The planet was validated based on TESS photometry, and its signal was distilled in radial velocity measurements. The joint analysis of photometric and Doppler data resulted in a multiplanetary model of the system. With a mass of 15M_{sun}_, radius of 2R_{sun}_, and orbital distance of 0.024au, the new planet WASP-84 c was classified as a hot super-Earth with the equilibrium temperature of 1300K. A growing number of companions to hot Jupiters indicates that a non-negligible part of them must have formed under a quiescent scenario such as disc migration or in situ formation., We provide the photometric time series for transits of WASP-84 b acquired with the ground-based telescopes: the 1.2m Trebur one-meter telescope (TRE120) at the Michael Adrian Observatory in Trebur (Germany) and the 0.9m Ritchey-Chretien telescope (OSN090) at the Sierra Nevada Observatory (Spain). The data were collected from 2016-2018. The details on observations and data processing are given in the paper., Financial support from the Severo Ochoa grant CEX2021-001131-S funded by MCIN/AEI/ 10.13039/501100011033, No

We describe the target selection and characteristics of the DESI Peculiar Velocity Survey, the largest survey of peculiar velocities (PVs) using both the fundamental plane (FP) and the Tully-Fisher (TF) relationship planned to date. We detail how we identify suitable early-type galaxies (ETGs) for the FP and suitable late-type galaxies (LTGs) for the TF relation using the photometric data provided by the DESI Legacy Imaging Survey DR9. Subsequently, we provide targets for 373533 ETGs and 118637 LTGs within the DESI 5-year footprint. We validate these photometric selections using existing morphological classifications. Furthermore, we demonstrate using survey validation data that DESI is able to measure the spectroscopic properties to sufficient precision to obtain PVs for our targets. Based on realistic DESI fiber assignment simulations and spectroscopic success rates, we predict the final DESI PV Survey will obtain ~133000 FP-based and ~53000 TF-based PV measurements over an area of 14000deg^2^. We forecast the ability of using these data to measure the clustering of galaxy positions and PVs from the combined DESI PV and Bright Galaxy Surveys (BGS), which allows for cancellation of cosmic variance at low redshifts. With these forecasts, we anticipate a 4% statistical measurement on the growth rate of structure at z<0.15. This is over two times better than achievable with redshifts from the BGS alone. The combined DESI PV and BGS will enable the most precise tests to date of the time and scale dependence of large-scale structure growth at z<0.15., These tables provide the target catalogs for the DESI peculiar velocity survey as well as all supplementary information to reproduce them and the methods presented in our paper., Financial support from the Severo Ochoa grant CEX2021-001131-S funded by MCIN/AEI/ 10.13039/501100011033, No