Related papers: The Origin of the Consistent Planetary Nebula Lumi…

Radio continuum observations at 1.4, 4.8 and 8.6 GHz of the two Planetary Nebulae (PNe) in the Sagittarius dwarf galaxy reveal the elongated shape of Wray 16-423 and the extreme compactness of He 2-436. He 2-436 is confirmed as subject to…

Accurate emission line fluxes from planetary nebulae (PNe) provide important constraints on the nature of the final phases of stellar evolution. Large, evolved PNe may trace the latest stages of PN evolution, where material from the AGB…

We have carried out a detailed analysis of the interesting and important very young planetary nebula (PN) Hen3-1357 (Stingray Nebula) based on a unique dataset of optical to far-IR spectra and photometric images. We calculated the…

We summarize observations with the Spitzer Infrared Spectrograph (IRS) of 571 starbursts (strong PAH emission features), 128 obscured AGN (strong silicate absorption), and 39 unobscured AGN (silicate emission). Sources range in luminosity…

We report deep long-slit spectroscopy of two Galactic compact planetary nebulae (PNe), PNG048.5+04.2 and PNG068.7+14.8, obtained using the 10.4m Gran Telescopio Canarias (GTC). These spectra cover a broad wavelength range of ~3630-10370 A,…

This paper presents deep spectra of 14 planetary nebulae (PNs) at a variety of angular distances from the center of the flattened elliptical galaxy NGC 4697. Both near the center and among the most outlying PNs we have found several…

We show that a strong P-Cygni feature seen in the far-UV spectra of some very hot (Teff >~ 85 kK) central stars of planetary nebulae (CSPN), which has been previously identified as CIII lambda 977, actually originates from NeVII lambda 973.…

We present the first determination of the galaxy luminosity function (LF) at z~4, 5, 6 and 7 in the rest-frame optical at lambda_rest~900 nm (z' band). The rest-frame optical light traces the content in low-mass evolved stars (~stellar mass…

We present emission line strengths, abundances, and element ratios (X/O for Ne, S, Cl, and Ar) for a sample of 38 Galactic disk planetary nebulae (PNe) consisting primarily of Peimbert classification Type I. Spectrophotometry for these PNe…

We present the results of a search for bright (-22.7 < M_UV < -20.5) Lyman-break galaxies at z ~ 6 within a total of 1.65 square degrees of imaging in the UltraVISTA/COSMOS and UKIDSS UDS/SXDS fields. The deep near-infrared imaging…

The emission line luminosity function of active galactic nuclei (AGN) is measured from about 3000 AGN included in the main galaxy sample of the Sloan Digital Sky Survey within a redshift range of $0<z<0.15$. The $\Ha$ and [OIII]$\lambda…

The recent discovery of a galaxy at z=7.3 with undetected optical emission lines and a blue UV to optical continuum ratio in JWST spectroscopy is surprising and needs to be explained physically. Here, we explore two possibilities that could…

Infrared spectra of NGC 7027 and NGC 6543 ranging from 2.4 to 45 micron were obtained with the Short Wavelength Spectrometer on board the Infrared Space Observatory. A first analysis of these spectra, with the aid of photo-ionization…

The Andromeda (M31) galaxy subtends nearly 100 sq. deg. on the sky, with severe contamination from the Milky Way halo stars whose surface density displays a steep gradient across the entire M31 field-of-view. Planetary Nebulae (PNe) are a…

The central stars of planetary nebulae (PNe) are natural targets for FUSE due to their UV brightness. The FUSE spectra of many PNe show absorption features due to circumstellar material in species ranging from H_2 and neutrals in the…

We determine the spectroscopic properties of ~1000 ostensibly star-forming galaxies at redshifts (z=4-10) using prism spectroscopy from JWST/NIRSpec. With rest-wavelength coverage between Lya and [S II] in the optical, we stack spectra as a…

Superluminous supernovae (SLSNe) are some of the brightest explosions in the Universe representing the extremes of stellar deaths. At the upper end of their distribution is SN\,2023taz, one of the most luminous SLSNe discovered to date with…

In this contribution, I will briefly review the development of the theory of photoionized gaseous nebulae, highlighting some of the key events. I will then present some recent developments of deep spectroscopy of planetary nebulae (PNe) and…

We present the results for the galaxy NGC 628 observed with the Planetary Nebulae Spectrograph (PN.S) equipped with the H$\alpha$ arm. With the third PN.S arm, the H$\alpha$ arm, we measure the H$\alpha$ fluxes, in addition to fluxes and…

The optical line and continuum emission in the very high ionization Galactic planetary nebula (PN) NGC 4361 (PN G294.1 +43.6), has been mapped with VLT MUSE Wide Field normal mode (4750-9300A) commissioning observations. The PN is larger…