星系天体物理

Cosmic rays (CRs), from active galactic nuclei (AGN) jets and supernovae (SNe), serve as a significant feedback mechanism influencing emission lines in narrow line region (NLR) clouds. These highly energetic particles, propelled by shocks,…

NGC 5253 is a nearby (D=3.6 Mpc) Blue Compact Dwarf galaxy, notable for its three massive young super star clusters (SSCs) and nitrogen enrichment. Its similarity to extreme star-forming galaxies at high redshift makes it a good local…

We investigate the origin of intervening cool MgII absorption detected in the spectra of background quasars and the nature of associated galaxies across a broad redshift range of $0.3 \le z \le 1.6$. Using nebular [O II]…

We present detections of auroral emission lines of [OIII], [OII], [SIII], and [SII] in deep JWST/NIRSpec spectroscopy for 41 star-forming galaxies at $z=1.4-7.2$ from the AURORA survey. We combine these new observations with 98 star-forming…

Individual stars in the Milky Way (MW) and its satellites have been shown to trace galaxy stellar mass dependent sequences in the $\alpha$-abundance ([$\alpha$/Fe]) vs metallicity ([Fe/H]) plane. Testing the universality of such sequences…

Mass loss is a key aspect of stellar evolution, particularly in evolved massive stars, yet episodic mass loss remains poorly understood. To investigate this, we need evolved massive stellar populations across various galactic environments.…

Cosmic rays (CRs) can significantly impact dense molecular clouds in galaxies, heating the interstellar medium (ISM) and altering its chemistry, ionization, and thermal properties. Their influence is particularly relevant in environments…

James Webb Telescope (JWST) observations have unveiled numerous galaxy candidates between $z \sim 9 - 16.5$, hinting at an over-abundance of sources at the bright-end of the UV luminosity function (UV LF) at z $\gsim$ 11. Complementarily,…

We use JWST/NIRSpec observations from the Assembly of Ultradeep Rest-optical Observations Revealing Astrophysics (AURORA) survey to constrain the shape of the nebular attenuation curve of a star-forming galaxy at z=4.41, GOODSN-17940. We…

We report detections of the [OIII]$\lambda$4364 auroral emission line for 16 galaxies at z=2.1-8.7, measured from JWST/NIRSpec observations obtained as part of the Cosmic Evolution Early Release Science (CEERS) survey program. We combine…

We present new astrophysical parameters for the open cluster NGC~6793 based on new CCD $UBV(RI)_{KC}$ photometry. We derived a reddening of $E(B-V) = 0.24 \pm 0.02$~mag and a heavy element abundance of $Z = 0.024$ ($[Fe/H] = +0.20$~dex).…

Compact steep spectrum (CSS) sources generally show weak Doppler boosting, yet some exceptions show multi-year-scale radio flux variability and high-energy activity. Since 2022, the CSS quasar 3C 138 has been in a radio high state…

Spectra of 6.7 GHz methanol masers from 21 pointings of known star-forming regions are reported. The C-band observations, using the Green Bank Telescope in full Stokes mode, have measured how polarization properties vary across the maser…

Red quasars (rQSOs) have been recognized as a short-lived, early stage in the evolutionary cycle of Active Galactic Nuclei (AGN), with fundamental differences in their intrinsic properties compared to blue quasars (bQSOs). In this work, we…

Low-luminosity active galactic nuclei (LLAGN; $L_{\rm bol} < 10^{42}$~erg~s$^{-1}$) may comprise a significant fraction of the local AGN population, yet their weak emission makes them difficult to detect. In this paper, we analyse 38 LLAGN…

We investigate the effects of source confusion expected in observations with GREX-PLUS, a JAXA L-class space infrared telescope mission candidate with a wide-field infrared camera covering 2-8 um with a field of view of 0.50 deg$^2$. For…

We present high-resolution magnetic field maps of the M17 SW molecular cloud using JCMT 850 $\mu$m dust polarization at a scale of 14$''$. The magnetic field exhibits a distinct arc-like structure that encircles three dense clumps (C1, C2,…

We present resolved HI observations of six dwarf galaxies drawn from a sample of baryon-dominated dwarf galaxy (BDDG) candidates previously identified using global HI spectra from ALFALFA and optical inclinations from SDSS, both of which…

JWST/NIRCam observations in the North Ecliptic Pole Time Domain Field (TDF) identify 4.4 micron counterparts for 206 of 211 radio sources with S(3 GHz) \gapprox 5 micro-Jy in a 65arcmin^2 field. One of the remaining radio sources is likely…

We analyze the line ratio of the $^{13}$CO (2-1) to $^{12}$CO (2-1) rotational transitions observed from new ALMA observations of 100 Giant Molecular Clouds (GMCs) that span the Large Magellanic Cloud. We measure a median line ratio of…