Related papers: The optical emission line spectrum of Mark 110

We describe the current status of two complementary programs to search for objects with strong emission lines in a ~300 A gap, centered at 9150 A, in the strong airglow emission. Both programs are being carried out with LRIS on the Keck II…

We present spectroscopy of emission lines for 81 Seyfert 1 and 104 Seyfert 2 galaxies in the IRAS 12$\mu$m galaxy sample. We analyzed the emission-line luminosity functions, reddening, and other gas diagnostics. The narrow-line regions…

(Abridged) We present the results of the photometric and spectroscopic identification of 110 hard X-ray selected sources (6e-15<F(2-10 keV)<4e-14 cgs) from 5 additional XMM-Newton fields, nearly doubling the original HELLAS2XMM sample. We…

Stars that exhibit prominent emission lines in their spectra are referred to as emission-line stars, encompassing a wide range of stellar types and indicative of intriguing physical properties. The Large Sky Area Multi-Object fiber…

This is the first paper in a series dedicated to the study of the emission-line and continuum properties of narrow line Seyfert 1 galaxies (NLS1s). We carried out a systematic search for NLS1s from objects assigned as ``QSOs'' or…

We present a new accurate catalog of narrow-line Seyfert 1 galaxies (NLS1s) in the southern hemisphere from the Six-degree Field Galaxy Survey (6dFGS) final data release, which is currently the most extensive spectroscopic survey available…

We investigate the high-ionization, narrow [Ne v] $\lambda$3427 emission line in a sample of over 340 ultrahard X-ray (14-195 keV) selected Active Galactic Nuclei (AGN) drawn from the BASS project. The analysis includes measurements in…

We performed 3D spectroscopic observations of Mrk 493 in order to investigate the Fe II emitting region and their possible connection with the Hydrogen emitting region. We found that there is a strong Fe II emission in an extensive region ~…

We analyze the rest-optical emission-line ratios of star-forming galaxies at 2.7<=z<6.5 drawn from the Cosmic Evolution Early Release Science (CEERS) Survey, and their relationships with stellar mass (M_*). Our analysis includes both line…

We present the first science results from our Hubble Space Telescope Survey for Lyman limit absorption systems (LLS) using the low dispersion spectroscopic modes of the Advanced Camera for Surveys and the Wide Field Camera 3. Through an…

SDSS J0924+0219 is the most glaring example of a gravitational lens with anomalous flux ratios: optical broad-band photometry shows image D to be a factor of 12 fainter than expected for smooth lens potentials. We report spectroscopy…

We present rest-frame optical emission-line flux ratio measurements for five $z>5$ galaxies observed by the JWST Near-Infared Spectrograph (NIRSpec) in the SMACS 0723 Early Release Observations. We add several quality-control and…

The absolute luminosity of the Fe Kalpha emission line from matter illuminated by X-rays in astrophysical sources is nontrivial to calculate except when the line-emitting medium is optically-thin to absorption and scattering. We…

Aims: We present preliminary results of the first Herschel spectroscopic observations of NGC7129 FIRS2, an intermediate mass star-forming region. We attempt to interpret the observations in the framework of an in-falling spherical envelope.…

We present photometric reverberation mapping of the narrow-line Seyfert 1 galaxy ESO399-IG20 performed with the robotic 15 cm telescope VYSOS-6 at the Cerro Armazones Observatory. Through the combination of broad- and narrow-band filters we…

We searched for the presence of extended emission-line regions (EELRs) around low-redshift QSOs. We observed a sample of 20 mainly radio-quiet low-redshift quasars (z<0.3) by means of integral field spectroscopy. After decomposing the…

Context. The study of BL Lac objects (BLL) detected in gamma-rays gives insights on the acceleration mechanisms in play in such systems and is also a valuable tool to constrain the density of the extragalactic background light. As their…

Recent ROSAT studies of narrow-line Seyfert 1 galaxies revealed these objects (with FWHM $H_{\beta} \le 2000 km s^{-1}$) generally show steeper soft X-ray spectra than broad line Seyfert 1's and that there are no AGN with broad lines and…

Wide Field Slitless Spectroscopy (WFSS) provides a powerful tool for detecting strong line emission in star forming galaxies (SFGs) without the need for target pre-selection. As part of the GLASS-JWST-ERS program, we leverage the…

We report the discovery of an extremely luminous galaxy lying at a redshift of z=5.74, SSA22-HCM1. The object was found in narrowband imaging of the SSA22 field using a 105 Angstrom bandpass filter centered at 8185 Angstroms during the…