At the beginning of 2018, Sarah Massalkhi took over the coordination of the seminars for the Molecular Astrophysics Group at the Instituto de Física Fundamental. The seminars are maximum one hour long, with 30 minutes presentation, and about 30 minutes of questions and interaction. They are held once per month and involve some serious business of doing science and eating cakes.
Talk by: Dr. Edward Montiel (University of California, Davis, USA)
Title: “Circumstellar Dust Shells: Clues to the Evolution of R Coronae Borealis Stars”
Abstract: The existence of extended, cold dust envelopes surrounding R Coronae Borealis (RCB) stars has been known about for over 30 years. RCB stars are an exotic group of extremely hydrogen-deficient, carbon-rich supergiants that are known for their spectacular declines in brightness (up to 8 mags) at irregular intervals. There are three possible origins of these envelopes: (1) they are fossil planetary nebulae (PNe), indicating that RCB stars formed via a final Helium-shell flash; (2) they are the remnant material from the merger of a CO and a He white dwarf binary, (3) they have been constructed from dust ejection events during the current phase of the central stars. In the first scenario we expect to find the shell H–rich, while in the remaining two scenarios the shell is H–poor. I have directly investigated the hydrogen abundance of the envelope surrounding R Coronae Borealis, itself, with archival observations from the Galactic Arecibo L-band Feed Array HI (GALFA-HI) Survey. Further, I have examined new and archival Spitzer Space Telescope and Herschel Space Observatory images in the far infrared and submillimeter of these envelopes to examine the morphology of these dusty shells. I will discuss all these results and their implications for the origins of the circumstellar material of RCB stars and the origins of RCB stars themselves.
Date: June 18, 2018
Talk by: Prof. Pepe Cernicharo (PI NANOCOSMOS, Instituto de Física Fundamental, CSIC)
Title: “Last results from NANOCOSMOS Gas Cell: Astrochemistry in the Lab”
Abstract: One of the aims of the Nanocosmos project is to develop a simulation gas chamber, also named gas cell, in order to emulate the interstellar and circumstellar gas chemistry. Radio astronomical receivers are proposed to be used as detectors for molecular spectroscopy and chemical reactivity experiments in the gas cell.
Date: June 1, 2018
Talk by: Dr. Hans Zinnecker (Deutsches SOFIA Institut (DSI), University of Stuttgart and Universidad Autonoma de Chile)
Title: “Airborne Infrared Astronomy with SOFIA”
Abstract: The Stratospheric Observatory for Infrared Astronomy (SOFIA) is an 80/20 joint project of NASA and the German Aerospace Center (DLR) to operate an airborne observatory. SOFIA is based on a Boeing 747SP wide-body aircraft that has been modified to include a large door in the aircraft fuselage that can be opened in flight to allow a 2.5 m diameter reflecting telescope access to the sky. This telescope is designed for infrared astronomy observations in the stratosphere at altitudes of about 12 kilometers. The primary science objectives of SOFIA are to study the composition of planetary atmospheres and surfaces; to investigate the structure, evolution and composition of comets; to determine the physics and chemistry of the interstellar medium; and to explore the formation of stars and other stellar objects. In this talk, we will review the capabilities of SOFIA, with an emphasis on molecular spectroscopy and astrochemistry studies.
Date: May 24, 2018
Talk by: Dr. Sandra Ignacia Ramírez Jiménez (ERC visiting professor for NANOCOSMOS, UEAM, Mexico)
Title: “The chemistry of Titan’s atmosphere”
Abstract: Titan, the biggest Saturn’s satellite, has long been considered as a natural laboratory where astrobiological interesting transformations can be studied on a planetary scale. In Titan’s atmosphere there is a permanent transformation of its major constituents, nitrogen (N2) and methane (CH4) into more complex organic compounds. Putative liquid water-ammonia (H2O-NH3) bodies likely to be present at the surface or subsurface of Titan, as crater melt pools or cryolavas have been proposed after the analysis of the information provided by the Cassini instrumentation.
A series of experiments have been conducted in which a simulated Titan’s atmosphere is subjected to cold-plasma irradiations. The identification of the gas-phase compounds is performed, and the chemical transformation that Titan’s aerosol analogues may suffer in the presence of ammonia, once they reach the satellite’s surface is presented.
The results are discussed in the context of Titan’s environment.
Date: Friday 20, April 2018
Cake by: Sarah Massalkhi