Browsing by Author "Sanchez, S. F."

Now showing 1 - 7 of 7
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    Herschel FIR counterparts of selected Lyα emitters at z ∼ 2.2 Fast evolution since z ∼ 3 or missed obscured AGNs?
    (2010) Bongiovanni, A.; Oteo, I.; Cepa, J.; Perez Garcia, A. M.; Sanchez-Portal, M.; Ederoclite, A.; Aguerri, J. A. L.; Alfaro, E. J.; Altieri, B.; Andreani, P.; Aparicio-Villegas, M. T.; Aussel, H.; Benitez, N.; Berta, S.; Broadhurst, T.; Cabrera-Cano, J.; Castander, F. J.; Cava, A.; Cervino, M.; Chulani, H.; Cimatti, A.; Cristobal-Hornillos, D.; Daddi, E.; Dominguez, H.; Elbaz, D.; Fernandez-Soto, A.; Schreiber, N. Foerster; Genzel, R.; Gomez, M. F.; Gonzalez Delgado, R. M.; Grazian, A.; Gruppioni, C.; Herreros, J. M.; Iglesias Groth, S.; Infante, L.; Lutz, D.; Magnelli, B.; Magdis, G.; Maiolino, R.; Marquez, I.; Martinez, V. J.; Masegosa, J.; Moles, M.; Molino, A.; Nordon, R.; del Olmo, A.; Perea, J.; Poglitsch, A.; Popesso, P.; Pozzi, F.; Prada, F.; Quintana, J. M.; Riguccini, L.; Rodighiero, G.; Saintonge, A.; Sanchez, S. F.; Santini, P.; Shao, L.; Sturm, E.; Tacconi, L.; Valtchanov, I.
    Ly alpha emitters (LAEs) are seen everywhere in the redshift domain from local to z similar to 7. Far-infrared (FIR) counterparts of LAEs at different epochs could provide direct clues on dust content, extinction, and spectral energy distribution (SED) for these galaxies. We search for FIR counterparts of LAEs that are optically detected in the GOODS-North field at redshift z similar to 2.2 using data from the Herschel Space Telescope with the Photodetector Array Camera and Spectrometer (PACS). The LAE candidates were isolated via color-magnitude diagram using the medium-band photometry from the ALHAMBRA Survey, ancillary data on GOODS-North, and stellar population models. According to the fitting of these spectral synthesis models and FIR/optical diagnostics, most of them seem to be obscured galaxies whose spectra are AGN-dominated. From the analysis of the optical data, we have observed a fraction of AGN or composite over source total number of similar to 0.75 in the LAE population at z similar to 2.2, which is marginally consistent with the fraction previously observed at z = 2.25 and even at low redshift (0.2 < z < 0.45), but significantly different from the one observed at redshift similar to 3, which could be compatible either with a scenario of rapid change in the AGN fraction between the epochs involved or with a non detection of obscured AGN in other z = 2-3 LAE samples due to lack of deep FIR observations. We found three robust FIR (PACS) counterparts at z similar to 2.2 in GOODS-North. This demonstrates the possibility of finding dust emission in LAEs even at higher redshifts.
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    IMF. shape constraints from stellar populations and dynamics from CALIFA
    (2016) Lyubenova, M.; Martın-Navarro, I.; van de Ven, G.; Falcon-Barroso, J.; Galbany, A.; Gallazzi, L.; Garcıa-Benito, R.; Gonzalez Delgado, R.; Husemann, B.; Sánchez Blazquez, Patricia; Marino, R. A.; Mast, D.; Mendez-Abreu, J.; Peletier, R. F. P.; La Barbera, F.; Sanchez, S. F.; Trager, S. C.; van den Bosch, R. C. E.; Vazdekis, A.; Walcher, C. J.; Zhu, L.; Zibetti, S.; Ziegler, B.; Bland-Hawthorn, J.
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    SDSS-IV MaNGA: A Star Formation-Baryonic Mass Relation at Kiloparsec Scales
    (2021) Barrera-Ballesteros, J. K.; Heckman, T.; Sanchez, S. F.; Drory, N.; Cruz-Gonzalez, I.; Carigi, L.; Riffel, R. A.; Boquien, M.; Tissera, P.; Bizyaev, D.; Rong, Y.; Boardman, N. F.; Hurtado, P. Alvarez
    Star formation rate density, sigma(SFR), has shown a remarkable correlation with both components of the baryonic mass kiloparsec scales (i.e., the stellar mass density and molecular gas mass density, sigma(*) and sigma(mol), respectively) for galaxies in the nearby universe. In this study, we propose an empirical relation between sigma(SFR) and the baryonic mass surface density (sigma(b) = sigma(mol,Av) + sigma(*), where sigma(mol,Av) is the molecular gas derived from the optical extinction, A(V)) at kiloparsec scales using the spatially resolved properties of the MaNGA survey, the largest sample of galaxies observed via integral field spectroscopy (similar to 8400 objects). We find that sigma(SFR) tightly correlates with sigma(b). Furthermore, we derive an empirical relation between sigma(SFR) and a second-degree polynomial of sigma(b), yielding a one-to-one relation between these two observables. Both sigma(b) and its polynomial form show a stronger correlation and smaller scatter with respect to sigma(SFR) than the relations derived using the individual components of sigma(b). Our results suggest that these three parameters are indeed physically correlated, suggesting a scenario in which the two components of the baryonic mass regulate the star formation activity at kiloparsec scales.
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    Stellar kinematics across the Hubble sequence in the CALIFA survey: general properties and aperture corrections
    (2017) Falcón Barroso, J.; Lyubenova, M.; Van De Ven, G.; Mendez Abreu, J.; Aguerri, J. A. L.; Garcia Lorenzo, B.; Bekeraite, S.; Sanchez, S. F.; Husemann, B.; Sánchez Blazquez, Patricia
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    The ALHAMBRA survey
    (2008) Moles, M.; Benitez, N.; Aguerri, J. A. L.; Alfaro, E. J.; Broadhurst, T.; Cabrera-Cano, J.; Castander, F. J.; Cepa, J.; Cervino, M.; Cristobal-Hornillos, D.; Fernandez-Soto, A.; Delgado, R. M. Gonzalez; Infante, L.; Marquez, I.; Martinez, V. J.; Masegosa, J.; del Olmo, A.; Perea, J.; Prada, F.; Quintana, J. M.; Sanchez, S. F.
    Here we describe the first results of the Advanced Large Homogeneous Area Medium-Band Redshift Astronomical (ALHAMBRA) survey, which provides cosmic tomography of the evolution of the contents of the universe overmost of cosmic history. Our novel approach employs 20 contiguous, equal-width, medium-band filters covering from 3500 angstrom to 9700 angstrom, plus the standard JHK(s) near-infrared (NIR) bands, to observe a total area of 4 deg(2) on the sky. The optical photometric system has been designed to maximize the number of objects with accurate classification by spectral energy distribution type and redshift, and to be sensitive to relatively faint emission features in the spectrum. The observations are being carried out with the Calar Alto 3.5 m telescope using the wide-field cameras in the optical, Large Area Imager for Calar Alto, and in the NIR, Omega-2000. The first data confirm that we are reaching the expected magnitude limits (for a total of 100 ks integration time per pointing) of AB <= 25 mag (for an unresolved object, signal-to-noise ratio = 5) in the optical filters from the blue to 8300 angstrom, and from AB = 24.7 to 23.4 for the redder ones. The limit in the NIR, for a total of 15 ks exposure time per pointing, is (in the Vega system) K-s approximate to 20 mag, H approximate to 21 mag, J approximate to 22 mag. Some preliminary results are presented here to illustrate the capabilities of the ongoing survey. We expect to obtain accurate redshift values, Delta z/(1+z) <= 0.03 for about five x 10(5) galaxies with 1 <= 25 (60% completeness level), and z(med) = 0.74. This accuracy, together with the homogeneity of the selection function, will allow for the study of the redshift evolution of the large-scale structure, the galaxy population and its evolution with redshift, the identification of clusters of galaxies, and many other studies, without the need for any further follow-up. It will also provide targets for detailed studies with 10 m class telescopes. Given its area, spectral coverage, and its depth, apart from those main goals, the ALHAMBRA survey will also produce valuable data for galactic studies.
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    The SELGIFS data challenge: generating synthetic observations of CALIFA galaxies from hydrodynamical simulations
    (2018) Guidi, G.; Casado, J.; Ascasibar, Y.; Garcia-Benito, R.; Galbany, L.; Sánchez Blazquez, Patricia; Sanchez, S. F.; Rosales-Ortega, F. F.; Scannapieco, C.
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    Which Galaxy Property is the Best Gauge of the Oxygen Abundance?
    (2022) Alvarez-Hurtado, P.; Barrera-Ballesteros, J. K.; Sanchez, S. F.; Colombo, D.; Lopez-Sanchez, A. R.; Aquino-Ortiz, E.
    We present an extensive exploration of the impact of 29 physical parameters in the oxygen abundance for a sample of 299 star-forming galaxies extracted from the extended Calar Alto Legacy Integral Field Area Survey sample. We corroborate that the stellar mass is the physical parameter that better traces the observed oxygen abundance (i.e., the mass-metallicity relation; MZR), while other physical parameters could play a potential role in shaping this abundance, but with a lower significant impact. We find that the functional form that best describes the MZR is a third-order polynomial function. From the residuals between this best functional form and the MZR, we find that once considered the impact of the mass in the oxygen abundance, the other physical parameters do not play a significant secondary role in shaping the oxygen abundance in these galaxies (including the gas fraction or the star formation rate). Our analysis suggests that the origin of the MZR is related to the chemical enrichment evolution of the interstellar medium due, most likely, to the buildup of stellar mass in these star-forming galaxies.