Seminars and Colloquia at ESO Santiago

September 2019

24/09/19 (Tuesday)
12:00, Urania room (ESO, Santiago) | ESO Santiago
TMT (30 minutes talk)
Talk — TBD
Alejandro Santamaria Miranda (Universidad de Valparaiso)

Abstract

TBD

26/09/19 (Thursday)
12:00, Urania room (ESO, Santiago) | ESO Santiago
TMT (30 minutes talk)
Talk — Photochemical reduction of CO2 on terrestrial planets
Svatopluk Civiš (J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences)

Abstract

 

The chemical evolution of early terrestrial planets is a long standing enigma which involves the uncertainty of chemical atmospheric composition and plausibility of biomolecules synthesis. In this study, new alternative scenario of the origin of methane on Mars and terrestrial planets is suggested. Martian and other planetary atmospheres rich in carbon dioxide can be abiotically converted into a mixture of methane and carbon monoxide by ‘methanogenesis’ on porous mineral photoactive surfaces upon soft UV irradiation. On young planets exposed to heavy bombardment by interplanetary matter, the process can be followed by synthesis of biomolecules in reprocessing of such reactive reducing atmosphere by impact-induced shock waves. The proposed mechanism of methanogenesis may help answer the question on the formation of methane and carbon monoxide by photochemical processes, the formation of biomolecules on early Earth and other terrestrial planets, and the source and seasonal variation of methane concentrations on Mars.

 

27/09/19 (Friday)
12:00, Urania room (ESO, Santiago) | ESO Santiago
TMT (30 minutes talk)
Talk — Multi-wavelengths observations of very inclined protoplanetary disks: probing dust vertical settling
Marion Villenave (ESO)

Abstract

The diversity of physical and structural conditions in protoplanetary disks – the birthplace of planets – might be responsible for the diversity observed in the exoplanet population. Studying protoplanetary disks could thus provide indirect constraints on planet formation processes. During this talk, I will present multi-wavelengths images of several protoplanetary disks that I analyzed during my 2-years studentship at ESO. The comparison of optical/infrared images, tracing small micron grains, with millimeter data, originating from the larger millimeter grains, provides crucial information on the efficiency of some evolutionary mechanisms. In particular, we explore dust vertical settling by observing a sample of 12 edge-on disks. These disks offer a unique orientation, allowing to observe directly the vertical structure of disks. We find that the vertically resolved disks sufficiently edge-on are compatible with having a millimeter dust scale height of about 1au at 100au, indicative of very efficient settling. This increasing dust density in the midplane likely enhance the efficiency of planet formation.

30/09/19 (Monday)
12:00, Urania room (ESO, Santiago) | ESO Santiago
TMT (30 minutes talk)
Talk — TBD
Camila Navarrete (ESO)

Abstract

TBD

October 2019

02/10/19 (Wednesday)
15:30, Urania room (ESO, Santiago) | ESO Santiago
ESO Colloquium
Talk — A contribution of star-forming regions and satellites to the z ~ 2 galaxy mass assembly
Anita Zanella (ESO)

Abstract

Giant star-forming regions ("clumps") with sizes < 1 kpc, masses ~ 10^9 Msun and blue colors are ubiquitous features of z ~ 2 galaxies. However, their formation phase has never been observed and their fate is highly uncertain. Are they born in-situ due to fragmentation of gas-rich disks or are they small companion galaxies that merged with the host? Do they migrate inward and contribute to the formation of the galaxy bulge or are they rapidly disrupted by stellar feedback?
To address these issues we are studying ~50 clumpy galaxies at z ~ 2, observed with ultra deep HST/WFC3 imaging and slitless spectroscopy. From spatially resolved emission line maps we discovered a bright, newly formed clump, in the very early phase of its collapse (age < 10 Myr). With a specific SFR ~ 30 times higher than the one of the whole galaxy, it behaves like a mini-starburst, showing that in-situ violent disk instability can induce highly efficient star formation. Our estimate of the clumps' lifetime (~ 500 Myr) favours scenarios where they survive stellar feedback and suggests that their inward migration is a plausible mechanism to form the bulge of the galaxy. I will also discuss the analysis of older clumps: their formation rate and age distribution as a function of distance from the galaxy nucleus put further constraints on their lifetime, the strength of stellar feedback, and their role in galaxy evolution.

03/10/19 (Thursday)
12:00, Urania room (ESO, Santiago) | ESO Santiago
TMT (30 minutes talk)
Talk — TBD
Aleksandra Solarz (ESO)

Abstract

TBD

07/10/19 (Monday)
12:00, Urania room (ESO, Santiago) | ESO Santiago
TMT (30 minutes talk)
Talk — TBD
Nathen Nguyen (ESO - Universidad de Chile)

Abstract

TBD

09/10/19 (Wednesday)
15:30, Library (ESO, Vitacura) | ESO Santiago
ESO Colloquium
Talk — TBD
Andres Jordan (Pontificia Universidad Católica de Chile)

Abstract

TBD

11/10/19 (Friday)
12:00, Urania room (ESO, Santiago) | ESO Santiago
TMT (30 minutes talk)
Talk — TBD
James Jackman

Abstract

TBD

14/10/19 (Monday)
12:00, Urania room (ESO, Santiago) | ESO Santiago
TMT (30 minutes talk)
Talk — SPIAKID (TBD)
Piercarlo Bonifacio (GEPI - Observatoire de Paris)

Abstract

TBD

15/10/19 (Tuesday)
12:00, Library (ESO, Vitacura) | ESO Santiago
TMT (30 minutes talk)
Talk — TBD
Rohan Naidu (Harvard-CfA, USA)

Abstract

TBD

16/10/19 (Wednesday)
12:00, Urania room (ESO, Santiago) | ESO Santiago
TMT (30 minutes talk)
Talk — 3D Kinematics of Stellar Substructures in the Magellanic Periphery
Lara Cullinane (Australian National University, Canberra, Australia)

Abstract

The Large and Small Magellanic Clouds (LMC/SMC), as two of the closest and most massive satellites of the Milky Way, have significant effects on the local Universe; including the distribution of ultra-faint satellites, and the orbits of tidal streams. Ongoing survey efforts with the Dark Energy Camera have revealed a wealth of low-surface-brightness stellar substructures in the periphery of the Clouds; characterising these structures will provide significant insight into the currently poorly-constrained masses and interaction history of the Clouds. In order to elucidate the properties of the structures, we have used 2df+AAOmega at the Anglo Australian Telescope to instigate a large-scale spectroscopic follow-up of stars across the Magellanic periphery. We are able to detect the kinematic signature of the Clouds up to projected distances of 23 degrees from the centre of the LMC. Combining our spectroscopically derived radial velocities with Gaia DR2 astrometry provides the first 3D kinematics for these regions. Our initial set of measurements, along a large substructure to the north of the LMC, reveal velocities near the extremity of the substructure are significantly different from those expected from an extrapolation of the LMC rotation curve. Our ultimate aim is to use these 3D kinematics to assess dynamical models of the Clouds; this will shed new light on the origin of the substructures, and the evolution of the Magellanic/Milky Way system.

18/10/19 (Friday)
12:00, Urania room (ESO, Santiago) | ESO Santiago
TMT (30 minutes talk)
Talk — TBD
Ruari Mackenzie (ETH Zurich)

Abstract

TBD

21/10/19 (Monday)
12:00, Urania room (ESO, Santiago) | ESO Santiago
TMT (30 minutes talk)
Talk — TMT talk
Bin Yang (ESO)

Abstract

TBD

22/10/19 (Tuesday)
12:00, Urania room (ESO, Santiago) | ESO Santiago
TMT (30 minutes talk)
Talk — TBD
Xiaoling Yu (Najing University)

Abstract

TBD

23/10/19 (Wednesday)
15:30, Urania room (ESO, Santiago) | ESO Santiago
ESO Colloquium
Talk — CEMP (TBD)
Piercarlo Bonifacio (GEPI - Observatoire de Paris)

Abstract

TBD

29/10/19 (Tuesday)
12:00, Library (ESO, Vitacura) | ESO Santiago
TMT (30 minutes talk)
Talk — TBD
Christian Herenz (ESO)
30/10/19 (Wednesday)
12:00, Library (ESO, Vitacura) | ESO Santiago
Talk — Exotic transients observed by the ePESSTO+ survey
Daniele Malesani (DTU, DK)

Abstract

(e)PESSTO(+) is an ongoing spectroscopic survey for transients, with the goal to classify and study in detail the wide zoo of extragalactic transients. While many of the observed targets are supernovae, the flexibility of the project allows to chase diverse and less understood objects, among which gamma-ray bursts, gravitational
wave sources, and fast radio bursts. I will describe the observations, results, and prospects for future studies of these classes of astronomical objects.

15:30, Library (ESO, Vitacura) | ESO Santiago
ESO Colloquium
Talk — TOPOS (TBD)
Elisabetta Caffau (GEPI - Observatoire de Paris)

Abstract

TBD

November 2019

05/11/19 (Tuesday)
12:00, Urania room (ESO, Santiago) | ESO Santiago
TMT (30 minutes talk)
Talk — TBD
Michael Fritz Sterzik (ESO)

Abstract

TBD

07/11/19 (Thursday)
12:00, Library (ESO, Vitacura) | ESO Santiago
Talk — TBD
Javier Abril (ESO)

Abstract

TBD

08/11/19 (Friday)
12:00, Library (ESO, Vitacura) | ESO Santiago
TMT (30 minutes talk)
Talk — AGNs with MATISSE
Violeta Gamez (Leiden, NL)

Abstract

Interferometry in the mid infrared benefits from several advantages for
the study of the cores of AGNs, namely optimum access to the innermost
dusty regions that lie very close to the central blackhole and a much
higher resolution compared to single dish telescopes. Already with MIDI
the old model of the dusty toroidal structure was challenged by
unveiling  substantial extended IR emission in the most unexpected
directions. MATISSE, the latest instrumentation in this field, expands
the reach of MIDI further into and beyond the mid-IR to the L and M
bands, adds more spectroscopic potential and aims at fully exploiting
multiple-baseline interferometry with the VLTI allowing, for the first
time, image reconstruction. This talk describes MATISSE and the first
results from  the commissioning data.

11/11/19 (Monday)
12:00, Urania room (ESO, Santiago) | ESO Santiago
TMT (30 minutes talk)
Talk — Mass loss trigger, observations and models in the intimate stellar environment
Claudia Paladini (ESO)

Abstract

TBD

12/11/19 (Tuesday)
12:00, Library (ESO, Vitacura) | ESO Santiago
TMT (30 minutes talk)
Talk — A new route to determining the ionising contribution to reionisation of the z~6 faint galaxy population
Romain Meyer (UCL, UK)

Abstract

The intergalactic medium (IGM) underwent its last cosmic phase transition as hydrogen was reionised by early galaxies in the first billion years. The timing of cosmic hydrogen reionisation has been extensively constrained by multiple probes over the last two decades. However, capturing the patchy and stochastic nature of reionisation has proved a challenge for all existing models, because the nature and the properties of the sources of reionisation are still unknown. Characterising the properties and the relative contributions of the sources of reionisation is thus crucial to complete our picture of cosmic history and galaxy evolution. However, it is thought that the majority contributors to the reionisation photon budget are too faint to be observed directly with current instruments. In this talk, I will show how the correlation of tracers of the faint population with the IGM transmission at z~6 can address this issue. We have assembled a large sample of Lyman-Break Galaxies (LBG), Lyman-Alpha Emitters (LAE) and metals absorbers in the field of several high-redshift quasars. We report the detection a statistical HI proximity effect in the Lyman-alpha forest of quasars which we attribute to the ionising contribution of the clustered faint population. Analytical modelling of the proximity effect is used to constrain the average escape fraction and ionising efficiencies of these subluminous contributors to reionisation. I will discuss the use of various IGM transmission statistics to correlate with galaxies as well as potential differences in the environment of LBGs, LAEs and metals in the early Universe. This novel approach provides a promising measurement of the ensemble-averaged contribution of faint galaxies to reionisation.

14/11/19 (Thursday)
15:30, Urania room (ESO, Santiago) | ESO Santiago
ESO Colloquium
Talk — TBD
Andres Jordán (Universidad Adolfo Ibañez)

Abstract

TBD

19/11/19 (Tuesday)
12:00, Library (ESO, Vitacura) | ESO Santiago
TMT (30 minutes talk)
Talk — TBD
Nikki Zabel (Cardiff, UK)

Abstract

TBD

26/11/19 (Tuesday)
12:00, Urania room (ESO, Santiago) | ESO Santiago
TMT (30 minutes talk)
Talk — RAMSES, a tool to compute an instrumental wavelength solution
Marcelo Tala (Landessternwarte, Zentrum für Astronomie der Universität Heidelberg)

Abstract

Current state-of-the-art echelle spectrographs derive the wavelength 

solution - the function that maps from pixel to wavelength space - in a 

purely empirical way, by  fitting polynomials to a sparse calibration 

lines spectrum. One way to ensure that the engineering data propagates 

from instrument building to operations is to use all design and 

engineering information in a physical model-based description of the 

instrument and use this to compute the wavelength solution. With the aim 

of fitting an echelle spectrograph model to real spectroscopic data to 

understand the instrument behavior, I developed RAMSES, a ray tracing 

software that calculates the optical path of individual rays through an 

echelle spectrograph from the slit to the detector. By including the 

effects of the environment on the physical properties of the optical 

elements that compose the spectrograph, I am able to reproduce some of 

the trends observed in the time series of the spectral line positions of 

the CARMENES calibration data and constraint the nature of the observed 

RV systematics.

28/11/19 (Thursday)
12:00, Urania room (ESO, Santiago) | ESO Santiago
ESO Thirty Minute Talks
Talk — TBD
Matthew Temple (Cambridge University)

Abstract

TBD

December 2019

02/12/19 (Monday)
12:00, Urania room (ESO, Santiago) | ESO Santiago
TMT (30 minutes talk)
Talk — TBD
Gabriele Pezzulli (ETH Zurich)

Abstract

TBD

03/12/19 (Tuesday)
12:00, Urania room (ESO, Santiago) | ESO Santiago
TMT (30 minutes talk)
Talk — TBD
Alessandro Razza (Universidad de Chile)

Abstract

TBD

04/12/19 (Wednesday)
12:00, Library (ESO, Vitacura) | ESO Santiago
TMT (30 minutes talk)
Talk — TBD
Stefano Cristiani (INAF, IT)

Abstract

TBD

January 2020

08/01/20 (Wednesday)
12:00, Urania room (ESO, Santiago) | ESO Santiago
TMT (30 minutes talk)
Talk — TBD
Kristine Wai Fun Lam (ETH Zurich)

Abstract

TBD

March 2020

31/03/20 (Tuesday)
12:00, Urania room (ESO, Santiago) | ESO Santiago
TMT (30 minutes talk)
Talk — TBD
Marco Berton & Luca Crepaldi

Abstract

TBD

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