galaxies

First author: Antonio D. Montero-Dorta Satellite galaxies undergo a variety of physical processes when they are accreted by groups and clusters, often resulting in the loss of baryonic and dark matter (DM) mass. In this work, we evaluate the predictions from the IllustrisTNG hydrodynamical simulation regarding the evolution of the matter content of satellites, focusing on a population that are accreted at $z>1$ and retain their identity as satellites down to $z=0$.

First author: Themiya Nanayakkara The confirmation of the presence of very massive quiescent galaxies at epochs only 1-2 Gyr after the Big Bang $[1-8]$ has challenged models of cosmology and galaxy formation $[9]$. Producing sufficient numbers of these requires abundant numbers of the host dark matter halos to have been assembled and sufficient time for star formation to proceed extremely quickly and then cease just as rapidly. Ground-based spectroscopy has suggested ages of 200-300 Myr$[3]$ at redshifts $3<z<4$.

First author: Kirsten L. Larson We develop a method to identify and determine the physical properties of stellar associations using Hubble Space Telescope (HST) NUV-U-B-V-I imaging of nearby galaxies from the PHANGS-HST survey. We apply a watershed algorithm to density maps constructed from point source catalogues Gaussian smoothed to multiple physical scales from 8 to 64 pc. We develop our method on two galaxies that span the distance range in the PHANGS-HST sample: NGC 3351 (10 Mpc), NGC 1566 (18 Mpc).

First author: Moritz M. M. Pleintinger The presence of radioactive $^{26}$Al at 1.8 MeV reflects ongoing nucleosynthesis in the Milky Way. Diffuse emission from its decay can be measured with gamma-ray telescopes in space. The intensity, line shape, and spatial distribution of the $^{26}$Al emission allow a study of these nucleosynthesis sources. The line parameters trace massive-star feedback in the interstellar medium due to its 1~My lifetime. We aim to deepen previous studies of the $^{26}$Al emission in the Milky Way, using all gamma-ray data including single and double events as collected with SPI on INTEGRAL from 2003 until 2020.

First author: J. ZuHone The number density of galaxy clusters as a function of mass and redshift is a sensitive function of the cosmological parameters. To use clusters for cosmological parameter studies, it is necessary to determine their masses as accurately as possible, which is typically done via mass-observable scaling relations. X-ray observables can be biased by multiphase gas and projection effects, especially in the case where cluster temperatures and luminosities are estimated from single-model fits to all of the emission with a given radius.

First author: Han Qu We predict the dwarf galaxy detection limits for the upcoming Chinese Space Station Telescope (CSST) survey that will cover 17,500 deg$^{2}$ of the sky with a wide field of view of 1.1 deg$^2$. The point-source depth reaches 26.3 mag in the $g$ band and 25.9 mag in the $i$ band. Constructing mock survey data based on the designed photometric bands, we estimate the recovery rate of artificial dwarf galaxies from mock point-source photometric catalogues.

First author: Qian-Hui Chen Bars play an important role in mixing material in the inner regions of galaxies and stimulating radial migration. Previous observations have found evidence for the impact of a bar on metallicity gradients but the effect is still inconclusive. We use the TYPHOON/PrISM survey to investigate the metallicity gradients along and beyond the bar region across the entire star-forming disk of five nearby galaxies. Using emission line diagrams to identify star-forming spaxels, we recover the global metallicity gradients ranging from -0.

First author: Ryota Ikeda We present a search and characterization of ultra-diffuse galaxies (UDGs) in the Frontier Fields cluster Abell 2744 at $z=0.308$. We use JWST/NIRISS F200W observations, acquired as part of the GLASS-JWST Early Release Science Program, aiming to characterize morphologies of cluster UDGs and their diffuse stellar components. A total number of 22 UDGs are identified by our selection criteria using morphological parameters, down to stellar mass of $\sim10^{7}M_{\odot}$.

First author: Karin M. Sandstrom JWST observations of polycyclic aromatic hydrocarbon (PAH) emission provide some of the deepest and highest resolution views of the cold interstellar medium (ISM) in nearby galaxies. If PAHs are well mixed with the atomic and molecular gas and illuminated by the average diffuse interstellar radiation field, PAH emission may provide an approximately linear, high resolution, high sensitivity tracer of diffuse gas surface density. We present a pilot study that explores using PAH emission in this way based on MIRI observations of IC 5332, NGC 628, NGC 1365, and NGC 7496 from the PHANGS-JWST Treasury.

First author: S. Samuroff We present direct constraints on galaxy intrinsic alignments using the Dark Energy Survey Year 3 (DES Y3), the Extended Baryon Oscillation Spectroscopic Survey (eBOSS) and its precursor, the Baryon Oscillation Spectroscopic Survey (BOSS). Our measurements incorporate photometric red sequence (redMaGiC) galaxies from DES with median redshift $z\sim0.2-1.0$, luminous red galaxies (LRGs) from eBOSS at $z\sim0.8$, and also a SDSS-III BOSS CMASS sample at $z\sim0.5$. We measure two point intrinsic alignment correlations, which we fit using a model that includes lensing, magnification and photometric redshift error.