Examinando por Autor "Giavalisco, M."

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Acceso Abierto
Another Servicing Mission to Extend Hubble Space Telescope’s Science past the Next Decade
(American Astronomical Society, 2019-09-30) López Morales, M.; France, K.; Ferraro, F. R.; Chandar, R.; Finkelstein, S.; Charlot, S.; Ballester, G. E.; Bersten, M. C.; Diego, J. M.; Folatelli, T.; García Senz, D.; Giavalisco, M.; Jansen, R. A.; Kelly, P. L.; Maccarone, Thomas J.; Redfield, S.; Ruiz Lapuente, P.; Shore, S.; Kallivayalil, N.; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
The Hubble Space Telescope has produced astonishing science over the past thirty years. Hubble's productivity can continue to soar for years to come provided some worn out components get upgraded. While powerful new ground-based and space telescopes are expected to come online over the next decade, none of them will have the UV capabilities that make Hubble a unique observatory. Without Hubble, progress in UV and blue optical astrophysics will be halted. Observations at these wavelengths are key for a range of unresolved astrophysics questions, ranging from the characterization of solar system planets to understanding interaction of galaxies with the intergalactic medium and the formation history of the universe. Hubble will remain our only source of high-angular resolution UV imaging and high-sensitivity UV spectroscopy for the next two decades, offering the ability for continued unique science and maximizing the science return from complementary observatories. Therefore, we recommend that NASA, ESA, and the private sector study the scientific merit, technical feasibility, and risk of a new servicing mission to Hubble to boost its orbit, fix aging components, and expand its instrumentation. Doing so would: 1) keep Hubble on its path to reach its unmet full potential, 2) extend the mission's lifetime past the next decade, which will maximize the synergy of Hubble with other upcoming facilities, and 3) enable and enhance the continuation of scientific discoveries in UV and optical astrophysics.
Acceso Abierto
Implications of Increased Central Mass Surface Densities for the Quenching of Low-mass Galaxies
(IOP Science Publishing, 2021-06-08) Guo, Y.; Carleton, T.; Bell, E. F.; Chen, Z.; Dekel, A.; Faber, S. M.; Giavalisco, M.; Kocevski, D. D.; Koekemoer, A. M.; Koo, D. C.; Kurczynski, P.; Lee, S. K.; Liu, F. S.; Papovich, C.; Pérez González, G.; National Science Foundation (NSF); National Aeronautics and Space Administration (NASA); National Research Foundation of Korea (NRF); Guo, Y. [0000-0003-2775-2002]; Carleton, T. [0000-0001-6650-2853]; Bell, E. F. [0000-0002-5564-9873]; Chen, Z. [0000-0002-2326-0476]; Dekel, A. [0000-0003-4174-0374]; Fabel, S. M. [0000-0003-4996-214X]; Giavalisco, M. [0000-0002-7831-8751]; Kocevski, D. D. [0000-0002-8360-3880]; Koekemoer, A. M. [0000-0002-6610-2048]; Koo, D. C. [0000-0003-3385-6799]; Kurczynski, P. [0000-0002-8816-5146]; Lee, S. K. [0000-0001-5342-8906]; Liu, F. S. [0000-0002-1064-1544]; Papovich, C. [0000-0001-7503-8482]; Pérez González, P. G. [0000-0003-4528-5639]
We use the Cosmic Assembly Deep Near-infrared Extragalactic Legacy Survey data to study the relationship between quenching and the stellar mass surface density within the central radius of 1 kpc (Σ1) of low-mass galaxies (stellar mass M* ≲ 109.5 M⊙) at 0.5 ≤ z < 1.5. Our sample is mass complete down to ∼109 M⊙ at 0.5 ≤ z < 1.0. We compare the mean Σ1 of star-forming galaxies (SFGs) and quenched galaxies (QGs) at the same redshift and M*. We find that low-mass QGs have a higher Σ1 than low-mass SFGs, similar to galaxies above 1010 M⊙. The difference of Σ1 between QGs and SFGs increases slightly with M* at M* ≲ 1010 M⊙ and decreases with M* at M* ≳ 1010 M⊙. The turnover mass is consistent with the mass where quenching mechanisms transition from internal to environmental quenching. At 0.5 ≤ z < 1.0, we find that Σ1 of galaxies increases by about 0.25 dex in the green valley (i.e., the transition region from star forming to fully quenched), regardless of their M*. Using the observed specific star formation rate gradient in the literature as a constraint, we estimate that the quenching timescale (i.e., time spent in the transition) of low-mass galaxies is a few (∼4) Gyr at 0.5 ≤ z < 1.0. The mechanisms responsible for quenching need to gradually quench star formation in an outside-in way, i.e., preferentially ceasing star formation in outskirts of galaxies while maintaining their central star formation to increase Σ1. An interesting and intriguing result is the similarity of the growth of Σ1 in the green valley between low-mass and massive galaxies, which suggests that the role of internal processes in quenching low-mass galaxies is a question worthy of further investigation.