Nine Billion Years of Neutral Gas Evolution

Session

Theory (and related observations) [chair: Romeel Dave]

2

Jul 29, 2019, 1:35 PM

Eridanus Auditorium (ESO)

35. From the ISM to the gas around galaxies: perspective from numerical simulations

Dusan Keres (UC San Diego)

7/29/19, 1:35 PM

Understanding of physical processes relevant for the evolution of the ISM is crucial for understanding of the galaxy evolution. Numerical simulations showed that several different physical mechanisms related to star formation play crucial role in the regularization and evolution of the ISM and that the same processes can also drive galactic outflows and affect the CGM. Stellar feedback via...

2. Galaxy formation with feedback from individual stars

Thorsten Naab (Max-Planck-Institute for Astrophysics)

7/29/19, 2:05 PM

I will present high-resolution simulations of the star forming multi-phase ISM investigating stellar feedback on all major thermal and non-thermal components like magnetic fields and cosmic rays. I will discuss the impact of stellar radiation, location of supernovae and cosmic rays on the distribution of molecular, neutral and ionized hydrogen. I will highlight limitations also of current...

11. The effects of local stellar radiation on non-equilibrium ISM chemistry and ISM line diagnostics

Alex Richings (Durham University)

7/29/19, 2:25 PM

The chemistry of ions and molecules in interstellar gas plays an important role in galaxy formation, as the abundances of different chemical species determine how quickly the gas can cool. Furthermore, understanding the gas chemistry is important for interpreting a wide range of ISM emission and absorption line diagnostics. Stellar radiation affects the ISM chemistry, as it ionises the gas and...

69. The evolution of the interstellar medium in merging galaxies

Jorge Moreno (Pomona College)

7/29/19, 2:45 PM

In this talk I will review the role of galaxy mergers in triggering star formation, and their effect on the interstellar medium. For many years, observations have suggested that star formation is enhanced in mergers. Recently, however, a number of IFU campaigns and HI surveys suggest that mergers also enhance the H$_2$ budget in galaxies, whilst leaving their HI content largely unaffected....

7. Prevalence of neutral gas in centres of merging galaxies

Rajeshwari Dutta (European Southern Observatory, Garching)

7/29/19, 3:35 PM

Galaxy mergers can funnel large quantities of gas to the central regions of galaxies, triggering intense bursts of star formation and fueling Active Galactic Nuclei (AGNs). Feedback from AGNs, both positive and negative, can in turn have a strong impact on the evolution of the host galaxies and their environment. We have recently conducted a study of the neutral gas in the centres of $z \leq...

47. The startling dynamics of HI-rich ultra-diffuse galaxies

Pavel Mancera Piña (Kapteyn Astronomical Institute & ASTRON)

7/29/19, 3:55 PM

I will present our main discoveries regarding the dynamics of HI-rich ultra diffuse galaxies (UDGs). Using a set of interferometric observations and a state-of-the-art 3D fitting technique we have derived reliable rotation velocities for a sample of seven isolated UDGs.

Surprisingly, these galaxies have very low circular velocities given their baryonic masses, which makes them shift off from...

20. How can HI dynamics be used to probe the connection between galaxies and their dark matter halos over cosmic time?

Federico Lelli (European Southern Observatory)

7/29/19, 4:15 PM

I will summarize recent results from the Spitzer Photometry and Accurate Rotation Curves (SPARC) database. To date, SPARC is the largest collection of galaxies with both high-quality HI rotation curves and NIR surface photometry. I will describe two classic methods to probe the connection between galaxies and dark matter (DM) halos: (I) fitting rotation curves with a prescribed DM halo...

24. How HI populates haloes: simulations vs. observations

Garima Chauhan (ICRAR/UWA)

7/29/19, 4:35 PM

All HI surveys are affected by selection effects, which in some cases can be quite complex. To understand these biases and how they affect our understanding of how galaxies populate dark matter halos, we have modelled HI emission lines of the galaxies in the semi-analytic model of galaxy formation SHARK, built on the LCDM SURFS suite of $N$-body simulations. We use the latter to create a mock...

48. Can we explain HI asymmetries in isolated galaxies without cold accretion?

Lourdes Verdes-Montenegro (Instituto de Astrofísica de Andalucía (CSIC))

Beyond the local Universe the vast majority of HI galaxies detected by SKA precursor/pathfinder blind HI surveys will be spatially unresolved, therefore it will be vital to squeeze as much information as possible out of the integrated profiles. Single dish observations of $z \sim 0$ galaxies already provide numerous example spectra of such unresolved sources. In this talk I will focus on HI...