Recent Talks

List of all the talks in the archive, sorted by date.


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Thursday July 21, 2022
Dr. Evanthia Hatziminaoglou
ESO

Abstract

Astrophysical observations at (sub)mm wavelengths (from ~300 micron to ~3mm)
allow us to study the cold and dense material in the Universe, hence probing
the formation of stars and planets, and the interstellar and circumgalactic
medium within galaxies across cosmic time. The current generation of
15m-class single-dish telescopes has delivered some of the first surveys at
(sub)mm wavelengths, allowing to go far beyond the previously optical-biased
view of the Universe. Follow-up observations with interferometers then
revealed in exquisite detail the morphology and kinematics of such (sub)mm
sources. However, it is now clear that without a transformative change in
the capabilities of single-dish facilities in the 2030s, interferometers
will soon become source-starved. The current generation of 15m-class single-
dish telescopes, with their limited fields of view, spatial resolutions, and
sensitivities, can only reveal the "peak of the iceberg" of the (sub)mm
source population, both for Galactic and extragalactic studies. These
limitations cannot be fully mitigated by interferometers, which are all
intrinsically affected by a low mapping speed and by the loss of diffuse
extended signals. The Atacama Large Aperture Submillimeter telescope
(AtLAST) project is a concept for a 50m diameter single dish observatory to
be built near the ALMA site. With its extremely large field of view (the goal
is ~2 degrees), spatial resolution (up to ~1'' at 350 micron) and sensitivity
to both point sources and large-scale structures, AtLAST will be
transformational for all fields of astronomy in the 2030s. In this talk I
will describe the EU Horizon2020-funded project that aims to deliver a
comprehensive design study for such a next-generation single-dish facility.


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Tuesday July 19, 2022
Dr. Youfen Wang
Beijing Astronomical Observatory

Abstract

We present a sample of 734 ultracool dwarfs using LAMOST DR7 spectra, i.e.,  those having a spectral type of or later than M6, including an L0.  All of these red or brown dwarfs are within 360 pc, with a Gaia G magnitude brighter than 19.2 mag, a BP-RP color redder than 2.5 mag  and an absolute G magnitude fainter than 9 mag. Their stellar parameters  (Teff, log g, and [M/H]) are consistent with being the Galactic thin-disk  population, which is further supported by their kinematics using LAMOST radial velocity plus Gaia proper motion and parallax.  A total of 77 are detected  with the lithium absorption line at 6708 A, signifying youth and substellar nature. We report on their kinematic ages estimated by the velocity dispersion. Thirty five close pairs are identified, of which the binarity of six is discovered for the first time.


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Thursday July 14, 2022
Dr. Jorge Sanchez-Almeida
IAC

Abstract

With the aim of detecting cosmological gas accretion onto galaxies of the local Universe, we examined the Ha emission in the halo of the 164 galaxies in the field of view of MUSE-Wide (Urrutia+19) with observable Ha (redshift < 0.42).  An exhaustive screening of the Ha images led us to select 118 reliable Ha emitting gas clouds. To our surprise, around 38 % of the time the Ha line profile shows a double peak centered at the rest-frame of the corresponding galaxy. We have explored several physical scenarios to explain this Ha emission, among which accretion disks around rogue  intermediate mass black holes (IMBHs) fit the observations best. I will describe the data analysis (to discard, e.g, instrumental artifacts and high redshift interlopers), the properties of the Ha emitting clumps (their fluxes, peak separation, and spatial distribution with respect to the central galaxy), and the arguments leading to the IMBH hypothesis rather than other alternatives (e.g., cosmological gas, expanding bubbles, or shocks in the circum galactic medium).


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Monday July 11, 2022
Jenny Smith
UCSB

Abstract

Microwave Kinetic Inductance Detectors (MKIDs) are superconducting detectors capable of single-photon-counting with energy resolution across the ultraviolet, visible, and infrared spectrum with microsecond timing precision. This unique combination of abilities enables a broad range of science goals from exoplanet detection to CMB measurements all with a single camera. In order to function as scientific cameras, MKIDs are multiplexed into kilo-pixel superconducting arrays that require large instantaneous readout bandwidths and resource-intensive real-time-processing.This talk will introduce MKID science then discuss the new digital readout system being developed on the Xilinx ZCU111 RFSoC platform. The talk will cover how to use modern tools including Vivado High-Level Synthesis (HLS), Vivado ML Intelligent Design Runs (IDR), and Python Productivity for ZYNQ (PYNQ) to create an adaptable, reprogrammable, open-source MKID readout system which is easier to use and more maintainable by scientists without sacrificing performance.

https://youtu.be/BzKQ6Ua_DGk

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Tuesday July 5, 2022
Dr. Carlos Luque, Dr. Nicola Caon
Instituto de Astrofísica de Canarias

Abstract

The first part of this talk will present an overview of the tool "module" and its main commands and flags. "module" provides the dynamic modification of the user’s environment for supporting multiple versions of an application or a library without any conflict. In the second part, we’ll first explain what Python virtual environments are, and describe three actual cases in which they are used. We’ll then illustrate a practical example to install a Python virtual environment, and duplicate it on a different platform.


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Friday June 24, 2022
Dr. José Manuel González Cava
Instituto de Astrofísica de Canarias/ EST

Abstract

El Telescopio Solar Europeo (EST) se encuentra actualmente en la fase de diseño preliminar. Uno de los principales objetivos de esta etapa es identificar y definir los requisitos técnicos que guiarán su desarrollo y posterior construcción. En este sentido, las herramientas de modelado y simulación constituyen un elemento clave para la caracterización de prestaciones y la evaluación de distintas alternativas técnicas. El objetivo de esta charla es presentar algunos de los modelos desarrollados por la Oficina de Proyectos de EST para la evaluación de los requisitos dinámicos del telescopio. En concreto, se profundizará en el modelo mecatrónico diseñado para el control del movimiento de los ejes de la estructura.

El seminario se impartirá en el Aula y se anima encarecidamente a asistir presencialmente. Habrá café tecnológico tras la charla, a las 11h30 en la cafetería.

Unirse a la reunión Zoom:
https://rediris.zoom.us/j/87861451633

Enlace de Youtube:

https://youtu.be/uCTyZVr76dc


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Tuesday June 21, 2022
Sepideh Eskandarlou, Dr. Mohammad Akhlaghi
CEFCA

Abstract

In the 16th SMACK, the very basics of LaTeX were introduced; showing how to make a basic document from scratch, set the printable size, inserting images and tables and etc. In this session, we will go into more advanced features that are also commonly helpful when preparing a professional document (while letting you focus on your exciting scientific discovery, and not have to worry about the style of the output). These features include automatically referencing different parts of your document using labels (this allows you to easily shuffle figures, sections or tables), making all references to various parts of your text click-able (greatly simplifying things for your readers), using Macros (to avoid repetition or importing your analysis results automatically), adding bibliography, keeping your LaTeX source, and your top directory clean, and finally using Make to easily automate the production of your document.


Lecture notes: https://gitlab.com/makhlaghi/smack-talks-iac/-/blob/master/smack-17-latex-b.md


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Wednesday June 15, 2022
Dr. David Nespral
Instituto de Astrofísica de Canarias

Abstract

FastCam is an instrument designed to obtain high spatial resolution images in the optical wavelength range from ground-based telescopes by using the Lucky Imaging technique. This technique is based on the idea of registering the instants of atmospheric stability, typically lasting just some milliseconds, using very short exposures. The instrument consists of a very low noise and very fast readout speed EMCCD camera capable of reaching the diffraction limit of medium-sized telescopes from 380 to 1000 nm. At the beginning of 2019, a new camera was commissioned. Now the instrument makes use of an Andor iXon DU-888U3-CSO#BV back-illuminated system containing a 1024x1024 pixel frame transfer CCD sensor from E2V Technologies. The pixel size is 13 microns and the camera allows up to 30 exposures per second. A new update of the camera acquisition software is currently being worked on. A complete characterisation of the detector is also being carried out in order to better understand and exploit all the performances of the instrument, applying particular configurations for each scientific case. A standard reduction of the data is also being implemented in order to offer it to all users of the instrument. The first FastCam was an instrument jointly developed by the Spanish Instituto de Astrofísica de Canarias (IAC) and the Universidad Politécnica de Cartagena which started in 2006. Since then, the IAC assumed the instrument and tested it on several telescopes of the OOCC, among them the Nordic Telescope (NOT) where images were obtained in the optical domain diffraction-limited with high contrast, reaching a resolution of 0.1”/px. Currently FastCam is a common-user instrument at the Cassegrain focus of the 1.52-meter Carlos Sánchez Telescope (TCS, Teide Observatory) where observations are being made to calibrate the detector with sky tests. The idea is that in the near future it will be installed in the NOT to finish the commissioning process of the new camera and the whole acquisition system so that this instrument can be used by the international community.

 


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Tuesday June 14, 2022
Dr. Klaus-Peter Schroder
Universidad de Guanajuato (Mexico)

Abstract

 

X-ray observations and non-detections of cool giants suggested a picture of a division
of warm solar-like giants with Coronae and cool inactive giants with cool winds instead,
first suggested by Linsky and Haish 1979. But in the meantime, photospheric magnetic field
has been detected in cool giants, and their chromospheric emission mostly surpasses the
"basal" flux, which is a minimum emission found in entirely inactive stars. Hence, the absence
of coronae in cool giants is not caused by a lack of magnetic activity! The real reason lies in
fundamental chromospheric physics, as we will show. Mayor evidence is provided by the 
Wilson Bappu effect: with lower gravity, density scale-heights increase. At the same time, 
chromospheric heating decreases and the "Athay point", at which the solar corona begins,
because chromospheric radiative cooling collapses by reaching full Hydrogen ionization, 
is not passed in giant chromospheres. A few case studies of eclipsing binaries with cool 
giants, providing a direct account of their chromospheric extent and density profiles, 
are presented to illustrate this explanation.  

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Friday June 10, 2022
Dr. Enrique Joven Álvarez
Instituto de Astrofísica de Canarias

Abstract

El uso de campos magnéticos no es habitual en la instrumentación desarrollada por el IAC. Sin embargo, en la actualidad dos proyectos hacen uso de los mismos con propósitos bien distintos. Por un parte DALI (PoP), un prototipo de haloscopio que busca los hipotéticos axiones (¿materia oscura?) a altas frecuencias. Y, por otra, la nueva infraestructura criogénica del laboratorio de detectores (LISA) que, para caracterizar los novedosos mKIDs, hace uso de un criostato de tipo ADR (Adiabatic Demagnetization Refrigerator), una tecnología que permite alcanzar temperaturas inferiores a 0.1 K. Y para ambas cosas necesitamos campos magnéticos intensos.