INAOE | Astrofísica | Seminarios
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2019-09-06 Galaxias Enanas Ultra Débiles, Reliquias del Universo Temprano
Area: Astrofísica
Investigador Invitado Víctor Hugo Ramírez Siordia
Filiación Institucional IRYA-Morelia
Resumen: Ver resumen Las Galaxias Enanas Ultra Débiles (UFDG) son las galaxias más débiles
detectadas a la fecha (<10^5 L_solar), son también los sistemas más
fuertemente dominados por materia oscura (con relaciones
masa-luminosidad de 10<M/L<10^4 [solares]). Sus poblaciones estelares
son muy viejas (\sim 13 Gyr) y de muy baja metalicidad ([Fe/H]<-2).
Cuentan con muy pocas estrellas observadas (unas 2000). Por lo tanto,
sus estrellas son consideradas como reliquias del universo primordial.
En esta plática discutiré sobre la naturaleza de estas galaxias y
presento mi trabajo sobre sus historias de formación estelar usando
métodos de estadística bayesiana para comparar la fotometría de sus
estrellas resueltas con la fotometría de poblaciones estelares teóricas.
Lugar-Hora Auditorio del Centro de Información - 12:00
2019-09-27 Lyman break analogs: local laboratories for star formation processes under extreme conditions
Area: Astrofísica
Investigador Invitado Thiago S Goncalves
Filiación Institucional Observatorio Valongo de Brasil
Resumen: Ver resumen The formation of stars in galaxies in the early Universe happened under different physical conditions from those commonly found at low redshift. The interstellar medium was turbulent and metal-poor, and gas densities were much higher on average. Nevertheless, detailed observations of such galaxies represent a considerable challenge due to the large distances involved. In this talk, I will give a review of the work currently being done by our research group focusing on the sample of Lyman break analogs, living fossils at low redshift that are selected based on their remarkable similarities to typical distant star-forming galaxies. I will show what properties appear to generate the high star formation rates observed and the perspectives for future work on this sample in upcoming observatories.
Lugar-Hora Auditorio del Centro de Información - 12:00
2019-10-04 Searching for galaxy overdensities in the distant universe — the case of submillimeter galaxies
Area: Astrofísica
Investigador Invitado Karín Menéndez-Delmestre
Filiación Institucional Observatorio Valongo de Brasil
Resumen: Ver resumen Galaxy evolution appears to be intimately connected to the environment and the galaxy position within the large-scale structure (LSS). Galaxy clusters represent the most extreme density environments and are ideal laboratories to investigate the interplay between galaxy evolution and the environment. As we explore out to higher redshifts, the local high-density environments of well-established, virialized clusters give way to looser LSS extending over regions of several megaparsecs in size (protoclusters). Different tracers have been used to map LSS in the distant universe (z>2); in particular, quasars and powerful radio galaxies. Considering that these are objects are only visible for a short period in the evolution of a massive galaxy, there is a significant fraction of forming clusters that remain unexplored. To identify the typical overdense regions at z > 2 we need tracers that are more abundant than these extreme objects. Clustering analysis indicate that at z~2 submm-selected ultra-luminous galaxies (submm galaxies, SMGs) reside in very massive halos, suggesting that these may trace high-density environments that likely evolve into the rich groups and clusters of galaxies we see today. Conversely, recent work has suggested that SMGs may be tracers of a broader range of environments, including structures with more modest masses caught in highly active periods. This suggests that since galaxies in these structures are likely caught during episodes of peak starbursts, SMGs may be tracers of a wider range of environments beyond the progenitors of today’s very rich clusters, opening a window for a more complete exploration of the details underpinning the process of galaxy evolution in concert with the assembly of LSS. We have completed a large observing program comprising deep narrow-band Ly-alpha imaging and multi-object spectroscopy using Palomar/Keck/Magellan telescopes to probe for galaxy overdensities in SMG environments at z~1-5 in 3 distinct fields: the HDF-North, ELAIS- N2 and COSMOS. With >100 spectroscopically-confirmed Ly-alpha emitters, we are in a position to gauge the level of galaxy overdensity in these regions. Furthermore, we have initiated a detailed study of the distribution in galaxy properties according to the maturity and evolving stage of LSS traced by SMGs, in an effort to explore the way galaxy and local environment relate to each other within the broader picture of a cosmologically-evolving LSS.
Lugar-Hora Auditorio del Centro de Información - 12:00
Area: Astrofísica
Investigador Invitado Ana Hidalgo
Filiación Institucional ESFM-IPN
Resumen: Ver resumen "Las galaxias de colores son galaxias con una intensidad muy alta en la
línea prohibida del oxigeno a 5007 A. No hay muchas galaxias que presenten
ese comportamiento, por lo que estamos estudiando sus características para
intentar entenderlas. En esta charla comentaremos las propiedades
fotométricas, químicas y de formación estelar de las mismas"
Lugar-Hora Sala 9309 - 12:30
2019-11-04 Lorentz invariance violation in astroparticle physics: subluminal and superluminal tests.
Area: Astrofísica
Investigador Invitado Humberto Martínez-Huerta
Filiación Institucional IFSC-USP, Brasil
Resumen: Ver resumen Astroparticle physics has recently reached a new status of precision due to the construction of new observatories, operating innovative technologies, and the detection of large numbers of events and sources. The precise measurements of cosmic and gamma rays can be used as a test for fundamental physics, such as the Lorentz invariance violation (LIV). Although LIV signatures are expected to be small, the very high energies and long distances that astrophysical sources involve, lead to an unprecedented opportunity for this task. In this talk, I will present different astrophysical LIV tests and the resulting exclusion limits in the photon sector, using the subluminal pair-production energy threshold shift and superluminal photon decays. Perspectives for the next generation of gamma-ray telescopes will also be addressed.
Lugar-Hora Aula 9309 (Ultimo piso de Docencia) - 12:00
2019-11-22 The Seyfert's Sexted, Decided
Area: Astrofísica
Investigador Invitado Omar López Cruz
Filiación Institucional INAOE
Resumen: Ver resumen The dynamical time in Compact Groups (CG) of Galaxies is much shorter than the Hubble time, they all should have already merged to form an elliptical galaxy like remnant. So, why do we still CG at low redshifts? We believe that we have answered this question by proposing secondary infall in the Seyfert's Sextet.
Lugar-Hora Auditorio del Centro de Información - 12:00
2019-11-29 tdb
Area: Astrofísica
Investigador Invitado tdb
Filiación Institucional AIP Postdam
Resumen: Ver resumen tbd
Lugar-Hora Auditorio del Centro de Información - 12:00

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05-07-2010 a las 14:08 por Webmaster

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