Caracterización de la cámara CAMELOT2

This work reflects the results of the complete characterization of CAMELOT2 (from in spanish CAmara MEjorada Ligera del OT) and is focused on determinate the best way to carry out the observations and pull out the best of this telescope. CAMELOT2 is the common user instrument of the IAC80 telescope, at the Teide Observatory. The IAC80 telescope has 82 cm of aperture and at its cassegrain focus is placed CAMELOT2, an instrument with a detector made by Spectral Instruments. It is a 4kx4k back illuminated CCD which operates in the optical wavelength range. It has a huge collection of lters which includes SDSS griz, Johnson UBVRI, Str omgrem uvby standards and many narrow lters. The pixels size is 15 which implies a pixel scale on-sky of 0.336 arcsec/pix. The theoretical eld of view must be 22 x 22 arcsminutes2 but, due to the vignetting caused by the lters, the useful eld of view is 10.6 x 10.6 arcminutes2. Due to this problem, all the analysis had to been carried out in the unvignetted region. In order to get a low readout time and low readout noise, the common use observing modes have 4 channels. Because of this, we performed all the tests for each individual channel and then we computed the mean for the 4 channels. A verifcation of the linearity response in all common observing modes was made. An important amount of images with at illumination and increasing exposure times were taken. It is clearly visible that all modes o er a satisfactory linear behavior. The saturation counts for every mode were determined and the maximum at counts for every mode were set to get the proper calibration at images. The unique way to check if the values of gain and readout noise are close to those provided by the manufacturer is from the images taken with CAMELOT2. A set of bias and ats images were taken and the values of gain and readout noise for the common observing modes were measured. This test makes sure that the results obtained are very similar to those provided in the datasheet of the CCD and, therefore, it is not su ering degradation. Despite the CCD is cooled to -105ºC, we have tested that the dark current is low enough and does not represent a high noise contribution. Again, many dark images with increasing exposure times were taken and analyzed. We found that, even in images with long exposure times (30 minutes), the dark current contribution is negligible and it is no necessary to take calibration dark images. The efect of the shutter opening/closin, time has been analyzed. This mechanical part of the camera blocks a tiny fraction of light at the beginning and at the end of the exposures. A set of images with very low exposure time were taken. In the very rst images is clearly seen the pattern of the shutter. It shows radial structure and depends on the polar angle in the image. It is hard to x its e ects and the best way to minimize them is to take science images with exposure times longer than the total time the shutter takes to open and close. The PSF shape of the stars in all the surface of the detector was checked. A set of stars in images with di erent lters were selected along the eld of view. The ellipticity of these stars were represented versus their position in the CCD, trying to gure out where comes rom the miss alignment. Further research is needed to solve this problem although our results point to a miss alignment between the primary and secondary mirrors. With the data provided by the previous sections an update of the exposure time calculator was made. Due to all the factor involved in the process of taking an astronomical image, it has not been possible to get the exact star lux, sky lux and the signal to noise ratio as they appear in a real image. It has been bounded the error sources and changes will be made. Finally, a practical test has been carried out using the previous results. Despite that the IAC80 is a small telescope, it is possible to obtain low-brightness images with the proper observation strategy. In this case, after 85 hour of observations, a low-brightness image of NGC1035 and its companion DF4 was obtained. The images were taken in SDSS rgi lters following a precise dithering pattern. After obtaining the images, an optimized data reduction procedure was applied paying special attention to systematic errors, telescope mirrors dirt and CCD pixel to pixel response. To ful ll this, a at image was made using the science images themselves. The results are images with a limit surface magnitude near to 29 magnitudes per arcsecond2 that can highly contribute to relevant current researches such as the presence of a galaxy lacking dark matter. Concluding this summary, small telescopes can still contribute to astronomy specially taking into account that they can o er more observation time per target at a lower cost as compared with their big brothers. The price to pay is that more nights are needed for some given projects. Finally, to reach good science results it is necessary to know all the parameters and characteristics about the detector like linearity, gain, noise sources and other particularities and prepare well the observations

The galaxy "missing dark matter" NGC1052-DF4 is undergoing tidal disruption

The existence of long-lived galaxies lacking dark matter represents a challenge to our understanding of how galaxies form. Here, we present evidence that explains the lack of dark matter in one of such galaxies: NGC1052-DF4. Deep optical imaging of the system has detected tidal tails in this object caused by its interaction with its neighbouring galaxy NGC1035. As stars are more centrally concentrated than the dark matter, the tidal stripping will remove a significant percentage of the dark matter before affecting the stars of the galaxy. Only ~7% of the stellar mass of the galaxy is in the tidal tails, suggesting that the stars of NGC1052-DF4 are starting only now to be affected by the interaction, while the percentage of remaining dark matter is <1%. This naturally explains the low content of dark matter inferred for this galaxy and reconciles these type of galaxies with our current models of galaxy formation.Comment: 18 pages, 9 figures, accepted for publication in ApJ; The main results of the paper are shown in figures 5 and

Introducing the LBT Imaging of Galactic Halos and Tidal Structures (LIGHTS) survey. A preview of the low surface brightness Universe to be unveiled by LSST

We present the first results of the LBT Imaging of Galaxy Haloes and Tidal Structures (LIGHTS) survey. LIGHTS is an ongoing observational campaign with the 2 × 8.4 m Large Binocular Telescope (LBT) aiming to explore the stellar haloes and the low surface brightness population of satellites down to a depth of μV ∼31 mag arcsec-2 (3σ in 10″ × 10″ boxes) of nearby galaxies. We simultaneously collected deep imaging in the g and r Sloan filters using the Large Binocular Cameras. The resulting images are 60 times (i.e. ∼4.5 mag) deeper than those from the Sloan Digital Sky Survey, and they have characteristics comparable (in depth and spatial resolution) to the ones expected from the future Legacy Survey of Space and Time (LSST). Here we show the first results of our pilot programme targeting NGC 1042 (an M 33 analogue at a distance of 13.5 Mpc) and its surroundings. The depth of the images allowed us to detect an asymmetric stellar halo in the outskirts of this galaxy whose mass (1.4 ± 0.4 × 108 M) is in agreement with the ΛCDM expectations. Additionally, we show that deep imaging from the LBT reveals low mass satellites (a few times 105 M) with very faint central surface brightness μV(0) ∼27 mag arcsec-2 (i.e. similar to Local Group dwarf spheroidals, such as Andromeda XIV or Sextans, but at distances well beyond the local volume). The depth and spatial resolution provided by the LIGHTS survey open up a unique opportunity to explore the 'missing satellites' problem in a large variety of galaxies beyond our Local Group down to masses where the difference between the theory and observation (if any) should be significant. © 2021 ESO.We acknowledge support from grant PID2019-107427GB-C32 from The Spanish Ministry of Science and Innovation. We acknowledge financial support from the European Union's Horizon 2020 research and innovation programme under Marie Sklodowska-Curie grant agreement No 721463 to the SUNDIAL ITN network, and the European Regional Development Fund (FEDER), from IAC project P/300624, financed by the Ministry of Science, Innovation and Universities, through the State Budget and by the Canary Islands Department of Economy, Knowledge and Employment, through the Regional Budget of the Autonomous Community. DZ acknowledges financial support from NSF AST-2006785. NC acknowledges support from the research project grant "Understanding the Dynamic Universe" funded by the Knut and Alice Wallenberg Foundation under Dnr KAW 2018.0067 and Chris Usher for interesting comments. DJS acknowledges support from NSF grants AST-1821967 and 1813708. JR acknowledges funding from the State Agency for Research of the Spanish MCIU through the `Center of Excellence Severo Ochoa' award to the Instituto de Astrofisica de Andalucia (SEV-2017-0709), financial support from the grants AYA2015-65973-C3-1-R and RTI2018-096228B-C31 (MINECO/FEDER, UE) as well as support from the State Research Agency (AEI-MCINN) of the Spanish Ministry of Science and Innovation under the grant `The structure and evolution of galaxies and their central regions' with reference PID2019-105602GB-I00/10.13039/501100011033. The LBT is an international collaboration among institutions in the United States, Italy and Germany. LBT Corporation partners are: The University of Arizona on behalf of the Arizona Board of Regents; Istituto Nazionale di Astrofisica, Italy; LBT Beteiligungsgesellschaft, Germany, representing the Max-Planck Society, The Leibniz Institute for Astrophysics Potsdam, and Heidelberg University; The Ohio State University, representing OSU, University of Notre Dame, University of Minnesota and University of Virginia. This research has made use of the NASA/IPAC Extragalactic Database (NED), which is funded by the National Aeronautics and Space Administration and operated by the California Institute of Technology. This work was partly done using GNU Astronomy Utilities (Gnuastro, ascl.net/1801.009) version 0.13.12-f50c. Work on Gnuastro has been funded by the Japanese Ministry of Education, Culture, Sports, Science, and Technology (MEXT) scholarship and its Grant-in-Aid for Scientific Research (21244012, 24253003), the European Research Council (ERC) advanced grant 339659-MUSICOS, and the Spanish Ministry of Economy and Competitiveness (MINECO) under grant number AYA2016-76219-P.Peer reviewe

TOI-2285b: A 1.7 Earth-radius planet near the habitable zone around a nearby M dwarf

We report the discovery of TO1-2285b, a sub-Neptune-sized planet transiting a nearby (42 pc) M dwarf with a period of 27.3 d. We identified the transit signal from the Transiting Exoplanet Survey Satellite photometric data, which we confirmed with ground-based photometric observations using the multiband imagers MuSCAT2 and MuSCAT3. Combining these data with other follow-up observations including high-resolution spectroscopy with the Tillinghast Reflector Echelle Spectrograph, high-resolution imaging with the SPeckle Polarimeter, and radial velocity (RV) measurements with the InfraRed Doppler instrument, we find that the planet has a radius of 1.74 +/- 0.08 R-circle plus, a mass of &lt;19.5 M-circle plus + (95% c.I.), and an insolation flux of 1.54 +/- 0.14 times that of the Earth. Although the planet resides just outside the habitable zone for a rocky planet, if the planet harbors an H2O layer under a hydrogen-rich atmosphere, then liquid water could exist on the surface of the H2O layer depending on the planetary mass and water mass fraction. The bright host star in the near-infrared (K-s = 9.0) makes this planet an excellent target for further RV and atmospheric observations to improve our understanding of the composition, formation, and habitability of sub-Neptune-sized planets

CIBERER : Spanish national network for research on rare diseases: A highly productive collaborative initiative

Altres ajuts: Instituto de Salud Carlos III (ISCIII); Ministerio de Ciencia e Innovación.CIBER (Center for Biomedical Network Research; Centro de Investigación Biomédica En Red) is a public national consortium created in 2006 under the umbrella of the Spanish National Institute of Health Carlos III (ISCIII). This innovative research structure comprises 11 different specific areas dedicated to the main public health priorities in the National Health System. CIBERER, the thematic area of CIBER focused on rare diseases (RDs) currently consists of 75 research groups belonging to universities, research centers, and hospitals of the entire country. CIBERER's mission is to be a center prioritizing and favoring collaboration and cooperation between biomedical and clinical research groups, with special emphasis on the aspects of genetic, molecular, biochemical, and cellular research of RDs. This research is the basis for providing new tools for the diagnosis and therapy of low-prevalence diseases, in line with the International Rare Diseases Research Consortium (IRDiRC) objectives, thus favoring translational research between the scientific environment of the laboratory and the clinical setting of health centers. In this article, we intend to review CIBERER's 15-year journey and summarize the main results obtained in terms of internationalization, scientific production, contributions toward the discovery of new therapies and novel genes associated to diseases, cooperation with patients' associations and many other topics related to RD research