相关论文: Faint recombination lines in Galactic PNe with [WC…

Over three decades of reverberation mapping (RM) studies on local broad-line active galactic nuclei (AGNs) have measured reliable black-hole (BH) masses for $> 100$ AGNs. These RM measurements reveal a significant correlation between the…

We present new low-resolution (R~800) optical spectra of 22 Galactic PNe with Spitzer spectra. These data are combined with recent optical spectroscopic data available in the literature to construct representative samples of compact (and…

The origin of the abundance discrepancy is one of the key problems in the physics of photoionized nebula. In this work, we analize and discuss data for a sample of Galactic and extragalactic HII regions where this abundance discrepancy has…

Double-peaked narrow emission lines (DPNELs) might be evidence for the existence of kpc-scale dual AGNs. There are so far large samples of objects with DPNELs in narrow emission line galaxies. Here, a systematic search is made to build a…

We infer the gas kinematics, diagnostics and ionic radial profiles, distance and central star parameters, nebular photo- ionization model, spatial structure and evolutionary phase of the PN NGC 6741 by means of long-slit high-resolution…

We report new observations of molecular anions with the Yebes 40m and IRAM 30m telescopes toward the cold dense clouds TMC-1 CP, Lupus-1A, L1527, L483, L1495B, and L1544. We detected for the first time C3N- and C5N- in Lupus-1A and C4H- and…

We have obtained deep spectra of 26 planetary nebulae (PNe) and 9 compact HII regions in the nearby spiral galaxy NGC 300, and analyzed them together with those of the giant HII regions previously observed. We have determined the physical…

We study the dust present in 56 Galactic planetary nebulae (PNe) through their iron depletion factors, their C/O abundance ratios (in 51 objects), and the dust features that appear in their infrared spectra (for 33 objects). Our sample…

The substantial number of binary central stars of planetary nebulae (CSPNe) now known ($\sim$50) has revealed a strong connection between binarity and some morphological features including jets and low-ionisation structures. However, some…

We have imaged the H92alpha and H75alpha radio recombination line (RRL) emissions from the starburst galaxy NGC 253 with a resolution of ~4 pc. The peak of the RRL emission at both frequencies coincides with the unresolved radio nucleus.…

Forbidden collisionally excited optical atomic transitions from high ionization potential (IP$\geq$54.8\,eV) ions, such as Ca$^{\mathrm{4+}}$, Ne$^{\mathrm{4+}}$, Fe$^{\mathrm{6+}}$, Fe$^{\mathrm{10+}}$, Fe$^{\mathrm{13+}}$,…

Chandra X-ray Observatory (CXO) images have revealed that the X-ray emitting regions of the molecule-rich young planetary nebulae (PNs) BD+30 3639 (BD+30) and NGC 7027 are much more asymmetric than their optical nebulosities. To evaluate…

We present a homogeneous analysis of the oxygen abundance in five H II regions and eight planetary nebulae (PNe) located at distances lower than 2 kpc and with available spectra of high quality. We find that both the collisionally excited…

Recent JWST observations have revealed a population of high-redshift galaxies ($z\gtrsim5$) exhibiting unexpectedly bright ultraviolet (UV) nitrogen emission lines. The strong N III] and N IV] features imply nitrogen-to-oxygen abundance…

This chapter presents a review on the latest advances in the computation of physical conditions and chemical abundances of elements present in photoionized gas H II regions and planetary nebulae). The arrival of highly sensitive…

We present a spectroscopic analysis of a broad-line active galactic nucleus (AGN) selected as little red dot at $z = 5.3$ behind the Bullet cluster (Bz5.3), based on JWST/NIRCam and NIRSpec data. The detection of strong FeII, OI, and CaII…

Accurate chemical compositions of star-forming regions are a critical diagnostic tool to characterize the star formation history and gas flows which regulate galaxy formation. However, the abundance discrepancy factor (ADF) between…

This paper is the first of a series specifically studying the abundances of sulfur, chlorine, and argon in Type II planetary nebulae (PNe) in the Galactic disk. Ratios of S/O, Cl/O, and Ar/O constitute important tests of differential…

In this paper, we present a semi-empirical calibration between the oxygen abundance and the $N2$ emission-line ratio for Low Ionization Nuclear Emission Regions (LINERs). This relation was derived by comparing the optical spectroscopic data…

We report on near-infrared medium-resolution spectroscopy of a sample of luminous and ultra luminous infrared galaxies (LIRGs-ULIRGs), carried out with SOFI at the ESO 3.5m New Technology Telescope. Because of wavelength dependence of the…