Postdoctoral fellowships in physics and astronomy at Universidad de Valparaíso, Chile

Cerro San Juan de Dios, Valparaíso, Chile

The Institute of Physics and Astronomy (IFA) at Universidad de Valparaíso (UV), Chile, is welcoming applications for postdoctoral grants. After an initial evaluation, selected applicants will be sponsored by their preferred faculty member to apply for 3-year FONDECYT postdoctoral positions. These fellowships include a competitive salary and individually managed funding for travel, publications, equipment and health insurance. Additional positions can become available in the near future from other personal or group grants at IFA.

Postdocs at IFA will have guaranteed access to exciting new datasets, like the SDSS-V Milky Way, Black Hole and Local Volume Mappers, that began operations in late 2020. Postdocs can also apply as PI to all professional observatories operating in Chile, including ALMA, ESO, Gemini-S and Magellan telescopes and are encouraged to lead their own projects and/or join ongoing efforts, according to their preference.

The IFA at Universidad de Valparaíso is located in the seaport City of Valparaíso, a UNESCO World Heritage Site. We are committed to maintain a diverse and inclusive work environment, which currently hosts 23 faculty members, 14 postdocs and 32 graduate students.

We are searching for postdoctoral candidates in the fields of stellar, galactic and extragalactic astrophysics, computational astrophysics, astronomical instrumentation, astrostatistics, astrometeorology, theoretical physics and cosmology. Details of our research areas and related faculty members can be found here and here.

Applications for FONDECYT fellowship sponsorship will be accepted until August 19, 2021, but earlier applications are strongly encouraged (ideally before 6 of August 2021).

FONDECYT fellowships only accept applications from recent PhD recipients (graduated between January 2018 and 26 August 2021). This period is extended backward by one year per child, for women who had children after January 2018. Other funding options do not carry these restrictions. FONDECYT fellowships are anticipated to start in April 2022.

If you would like to be contacted by our faculty members to apply for sponsorship, or to other postdoctoral positions, please fill this form.

For the first time astronomers name a cluster of stars as Valparaíso 1

The discovery, in which astronomers from the Institute of Physics and Astronomy of the University of Valparaíso and the Millennium Institute of Astrophysics (MAS) participated, suggests that many formations of this type may be hidden in the inner regions of our galaxy and that until now it has been impossible to observe.

Please continue reading this new in the Spanish version

Zona donde se encuentra “escondido” el cúmulo Valparaíso 1. Crédito SDSS. En la esquina de la izquierda se muestra una imagen de la zona en el infrarrojo. Los puntos rojos muestran las estrellas que pertenecen al cúmulo, seleccionadas con la ayuda de datos de movimientos propios y distancias que provienen de Gaia DR2.

Trojans in our Solar System

In 1772 Lagrange identified five points of stability between three bodies: the Sun, a planet, and a small object. In this context, stability refers to the fact that at these points the small object will be equally attracted by the two bodies, with the same intensity. The objects (asteroids) share the same orbit as the planet are called Trojans, and are located in two stable Lagrange points, called L4 and L5, where: L4, is 60º in front of the planet and L5, 60º behind it. 

According to Lagrange, large amounts of dust and asteroids (the size of meters to kilometers) should accumulate at these points around Jupiter, and such asteroids were first observed in 1906. With the advance of technology and new observations, hundreds of Trojans have been identified in the Solar System. However, it is not yet very clear how these objects are formed or why it seems that there are more objects at one Lagrange point than at the other. Despite the existence of these equilibrium points, it is not clear how dust and rocks accumulate in those regions, nor what are the dynamics of their evolution.

Moreover, considering that the solar system formed from, the Solar System formed from a primordial disk that had a large gas(99%) and little dust (1%), the origin of the Trojans must be closely related to this gas-dust interaction.

To answer this question, an international group of astronomers, led by Matías Montesinos, research associate of the Max Planck Tandem Group and collaborator of the Núcleo Milenio de Formación Planetaria, NPF, theoretically studied this interaction, thus reconstructing the origin and remote past of the Trojans around a Jupiter-type planet.

Six of the eight authors of this work belong to the NPF. Besides Montesinos, Juan Garrido-Deutelmoser, postgraduate student; Johan Olofsson, associate researcher; Jorge Cuadra, associate researcher; Amelia Bayo, director of NPF; and Mario Sucerquia, postdoctoral researcher participated. The research was published in the prestigious scientific journal Astronomy & Astrophysics.

 “We modeled the evolution of a protoplanetary disk through hydrodynamic simulations, taking into account the interactions of a Jupiter-type planet with the gas and dust content of the disk. In addition, we considered an energy equation, in which the gas is heated by the star, and cooled gradually as it radiates, allowing us to model more realistically the thermodynamics and dynamics of the process,” explains Montesinos.

The researchers concluded that the dust does indeed accumulatein the Lagrangian points, which occurs in a short period of time. In about 10,000 years, dust should accumulate at L4 and L5, in an amount approximately equal to a few moon masses. This dust is accumulated by the gravitational interaction between Jupiter and the primordial gas of the protoplanetary disk. 

“We also notice certain peculiarities in the final formation of the Trojans. For example, we discovered a natural asymmetry where L5 accumulates more mass than L4 (mass than L4, which was an unexpected result). In addition, we found that the dust reservoir for the assembly of a Trojan is only in the same orbital region of the planet. That is, the Trojans “trapped” in a Lagrangian point do not come from regions far from the planet (e.g., the outer edges of the disk), but from zones co-rotating with it, in the same orbit as the planet“, indicates Montesinos. The astrophysicist adds that this means, for example, that these Trojans would share the chemical composition of the planet they accompany, at least to the first order.

Amelia Bayo, who is also an academic in the Instituto de Física y Astronomía at Universidad de Valparaíso, says that one of the things that she finds most interesting about the work is that it connects very directly the “world” of exoplanet research, with what we can see in other solar systems, with our solar system. “We know for example that there are many planetary systems that are super different from our solar system, but it seems that the accumulation of dust at these points and with these asymmetries should be a common feature of the planetary zoo,” she says.

Future work

An interesting point for researchers is to consider the interactions with other planets in the Solar System that could influence the formation of the Trojans.

“As future observational work, it would be interesting to try to detect these primordial Trojans in certain young systems. There are many disks around young stars, which resemble what the Solar System once was. In some of them, cavities, supposedly formed by planets, have been observed, but it has been very difficult to detect Trojans. Even though most of the planets, supposedly responsible for the opening of those cavities, have not yet been detected, , there should be two swarms of Trojans, one in front of the planet at L4, and another following behind at L5. Finding these two large accumulations of dust inside a cavity would be an indirect clue to the presence of a hidden planet in it,” concludes Matias Montesinos.

Link to the article

Fuente: Carol Rojas NPF