Journal Club


"Listening of the Galaxy with a Wire"

Dr. Miljenko Cemeljic (CAMK, Warsaw)

With the era of Software Defined Radio, amateur radio-astronomy obtained a new impulse. It is possible to build a small radio telescope at low cost (less than 100 eur) and use it to observe the neutral hydrogen line (21cm) in our Galaxy and also radio emissions from the Sun and Jupiter. There are even amateur observations of pulsars with such devices. Such projects, involving astronomy, radio technics and data analysis are a welcome feature for STEM teaching at various levels. I will explain how to build such a telescope and observe the Galaxy rotation curve.


"The Properties of Wind Generated From Accretion Flows"

Amin Mosallanezhad (CAMK, Warsaw)

Black hole astrophysics is a rapidly growing field of study that has captured the attention of many researchers in recent years. The extreme physical conditions and super-gravity of black holes make them a fascinating subject of research. Black holes play a fundamental role in many active phenomena in the universe, such as active galactic nuclei, stellar-mass black holes, ultra-luminous X-ray sources, gamma-ray bursts, and stellar and galactic jets. Moreover, black hole astrophysics is closely related to other crucial topics in astrophysics. Observational evidence has established a strong correlation between the mass of the black hole and the luminosity, stellar velocity dispersion, or stellar mass in the galaxy spheroid. This correlation suggests that central supermassive black holes (SMBHs) play a critical role in the formation and evolution of galaxies. Active galactic nuclei (AGN) emit intense radiation, jets, and wind, which can spread from the interior of the galaxy to the spatial scale of the dark matter halo outside the galaxy. These outputs can interact with the interstellar medium, affecting the temperature, density, and spatial distribution of these gases, and ultimately impacting the formation of stars in the galaxy and even leading to the extinction of the galaxy. At the extra-galactic scale, the nuclear output of these active galaxies can interact with the gas in the ring galaxy medium and the galaxy's halo, thereby affecting the gas supply of the galaxy's outer gas to the galaxy, which in turn will also affect the star formation and galaxy evolution.