Litclub
What is LitClub?
The goal is to provide a platform for free and casual discussion of scientific topics while also serving as a good way to improve communication and presentation skills. The general idea is to have a place for everybody to discuss new and interesting research topics that's been going on in other fields of Astronomy, Physics and sometimes even other sciences, as well as for more senior researchers at the observatory to share some of their expertise.
When?
Every two weeks on Wednesday, at 11.00.
Who?
Anyone! Students are especially encouraged to join, but this should appeal to anyone who'd like to learn more about science outside their own sphere of influence/experience.
How?
Given their availability, someone is assigned to present a paper of their choice from the list below and is usually given notice of a few days in advance. This is to ensure that LitClub doesn't end up taking too much time in prep., as we want to try to ensure that it remains casual. The presenter can choose however they'd like to present the paper. The goal is not a polished presentation, but to get the point of a paper across enough to spark discussion.
Where?
The conference room, for in-person attendees, and the rest via zoom. The current plan is to facilitate this hybrid configuration to accommodate for as many people as possible.
If you have questions, suggestions for topics/papers, or want to give a talk please write a mail to astro-literature@lists.fau.de
Meetings
Semi-inaugural meeting - 15-06-2022: Jakob Stierhof
Spectrally resolved imaging with the solar gravitational lens [1]
- The paper proposes using diffraction by the solar gravitational field as a "lens" to image exoplanets. They suggest that a telescope placed at the focal length of this lens would be able to capture images of exoplanets.
- They show that the light remains relatively unchanged in the optical and infrared regimes and describe a method of reconstruction of images of faint and extended sources. They also suggest that the telescope must include an external occulter (starshade) that can block sunlight which would preclude capturing any information bent by the corona.
29-06-2022: Aafia Zainab
Hydrodynamical backflow in X-shaped radio galaxy PKS 2014-55 [2]
- X-shaped radio galaxies show radio emission in the shape of an "X". Models attempting to explain this include (i) re-orientation of the black hole spin, (ii) superposition of jets from two SMBHs, or (iii) hydrodynamical backflows from the jets which are suggested to be deflected by the galaxy's ISM.
- The paper reports analysis of a MEERKAT radio image of galaxy PKS 2014-55 to support the third model, concluding that the "double boomerang" structure they see is evidence of backflows from the ISM, and that re-orientation of spin is unlikely in this case.
13-07-2022: Jonathan Knies
The Habitable-zone Planet Finder Detects a Terrestrial-mass Planet Candidate Closely Orbiting Gliese 1151: The Likely Source of Coherent Low-frequency Radio Emission from an Inactive Star [3]
- Radio emission from a planet orbiting an M-dwarf star points to new method of detecting exoplanets. The radio emission is due to sub Alfven interactions between the star's plasma and the planet's magnetic field. Something similar can also be seen in the Jupiter-Io system.
- The paper reports analysis of data from HPF, TESS etc. and reports an orbital period of the planet of about 2 days, placing it at 18 R_*. The planet does not show up using the transit method, which would have required a very small inclination angle suggesting that it would've been missed if not for the radio detection.
There is an astrobite on this topic! [4]
09-11-2022: Federico Zangrandi
First JWST observations of a gravitational lens: Mass model from new multiple images with near-infrared observations of SMACS J0723.3−7327 [5]
- The paper reports analysis of new JWST results combined with archival HST and MUSE data of the cluster SMACS J0723.3−7327. They present their strong lensing model which has resulted in more than double the number of 'multiple' images found with HST data, showing how useful JWST can be.
- Among the galaxies that they estimate redshifts for, they find one with z~7.5 making it the highest known redshift galaxy.
Litclub Paper List
We collect potentially interesting papers in an ADS library to give some inspiration (a separate library lists the already presented papers). But everyone is encouraged to present any interesting scientific work, not restricted to astronomy! Also, in case you found interesting papers feel free to add them to the list below (create sections as required).
X-ray astronomy
- Electromagnetic extraction of energy from Kerr black holes (Blandford-Znajek mechanism): Blandford, Znajek, MNRAS 179, 433, 1977 [1] (although, astrophysically, the Blandford-Payne mechanism likely contributes more to jet launching, e.g., Livio, Ogilvie, Pringle, ApJ 512, 100, 1999)
- "The corona contracts in a black-hole transient": Kara et al., Nature 565 198, 2019 [2], although this result is disputed (e.g., arxiv/2112.08116)
- Connection of FRBs and magnetars: "INTEGRAL Discovery of a Burst with Associated Radio Emission from the Magnetar SGR 1935+2154" (Mereghetti, 2020ApJ...898L..29M)
- "Discovery of oscillations above 200 keV in a black hole X-ray binary with Insight-HXMT" (Ma et al., 2021NatAs...5...94M)
- "Cygnus X-1 contains a 21-solar mass black hole—Implications for massive star winds" (Miller-Jones 2021Sci...371.1046M)
- EuCAPT White Paper: Opportunities and Challenges for Theoretical Astroparticle Physics in the Next Decade (Batista et al., arxiv.org/abs/2110.10074) - perhaps too long but really interesting summary
- Dark Energy Survey 3 Year Results (e.g., http://adsabs.harvard.edu/abs/2021arXiv210513549D)
Aliens? :0
- Estimating the prevalence of malicious extraterrestrial civilizations (Caballero 2022arXiv220511618C) [6]
Cosmology
- Is the Expansion of the Universe Accelerating? All Signs Still Point to Yes: A Local Dipole Anisotropy Cannot Explain Dark Energy [7]
Statistics
- "STATISTICS, HANDLE WITH CARE: DETECTING MULTIPLE MODEL COMPONENTS WITH THE LIKELIHOOD RATIO TEST" (Protassov, 2002ApJ...571..545P)
Some more extravagant stuff
- The Breakthrough Listen Search For Intelligent Life Near the Galactic Center (Gajjar et al., ApJ 162, 33, 2021)
- An Objective Bayesian Analysis of Life's Early Start and Our Late Arrival (Kipping, 2020, https://arxiv.org/abs/2005.09008)
Non-astrophysics
- creating unique random numbers using the quantum noise of the vacuum: Gabriel et al., Nature Photonics 4, 711, 2010