Related papers: CLEAR: High-Ionization [Ne V] ${\lambda}$3426 Emis…

We present a detailed analysis of the most luminous and obscured Active Galactic Nuclei (AGNs) detected in the ultra-hard X-ray band (14-195 keV) by Swift/BAT. Our sample comprises 21 X-ray luminous (log $L_X/{\rm erg\,s^{-1}}>44.6$, 2-10…

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 investigate spatially-resolved emission-line ratios in a sample of 219 galaxies ($0.6<z<1.3$) detected using the G102 grism on the \emph{Hubble Space Telescope} Wide Field Camera 3, taken as part of the CANDELS Ly$\alpha$ Emission at…

We use deep spectroscopy from the Hubble Space Telescope (HST) Wide-Field-Camera 3 (WFC3) IR grisms combined with broad-band photometry to study the stellar populations, gas ionization and chemical abundances in star-forming galaxies at…

Detecting Active Galactic Nuclei (AGN) in galaxies dominated by powerful nuclear star formation and extinction effects poses a unique challenge. Due to the longer wavelength emission and the ionization potential of Ne^3+, infrared [Ne V]…

We report the discovery of [NeV]3426 emission, in addition to HeII4686 emission, in six compact star-forming galaxies. These observations considerably increase the sample of eight such galaxies discovered earlier by our group. For four of…

We select a sample of 1,437 active galactic nuclei (AGN) from the catalog of the Sloan Digital Sky Survey (SDSS) galaxy properties from the Portsmouth group by detection of the high-ionization [Ne V] 3426 \r{A} emission line. We compare the…

We report the discovery of the high-ionisation [Ne v] 3426A emission line in the spectra of five blue compact dwarf (BCD) galaxies. Adding the three previously known BCDs with [Ne v] emission, the entire sample of such galaxies now contains…

We used Spitzer/IRS spectroscopic data on 426 galaxies including quasars, Seyferts, LINER and HII galaxies to investigate the relationship among the mid-IR emission lines. There is a tight linear correlation between the [Ne V]14.3 um and…

In the last few years, prominent high-ionization nebular emission lines (i.e., OIII], CIII], CIV, HeII) have been observed in the deep UV spectra of z~5-7 galaxies, indicating that extreme radiation fields characterize reionization-era…

We use Hubble Space Telescope WFC3 G102 and G141 grism spectroscopy to measure rest-optical emission-line ratios of 533 galaxies at $z\sim1.5$ in the CANDELS Ly$\alpha$ Emission at Reionization (CLEAR) survey. We compare…

We report the first detections of [Ne V] 14.3 {\mu}m and [Ne VI] 7.7 {\mu}m at high confidence (S/N>=6) in the nuclear region of the nearby spiral galaxy M83. Emission line maps of these high ionization lines show several compact…

We present a census of local active galactic nuclei (AGN) at a redshift of $z\leq0.025$ selected using the high-ionization [Ne v] $\lambda14.32\,\mu$m emission line from the Infrared Database of Extragalactic Observables from Spitzer…

We present a 24 um-selected spectroscopic sample z > 0.13 (median z = 0.41) in the Lockman Hole field, consisting of 4035 spectra. Our aim is to identify AGNs and determine their fraction in this mid-infrared selected sample. In this work,…

We use the narrow [Ne v] $\lambda$3427 emission line detected in the recently published JWST spectra of two galaxies, at z = 6.9 and 5.6, to study the key properties of the active galactic nuclei (AGN) and the supermassive black holes…

Studying the behavior along the galaxy main sequence is key in furthering our understanding of the possible connection between AGN activity and star formation. We select a sample of 1215 AGN from the catalog of SDSS galaxy properties from…

Spectroscopic studies of extreme-ionization galaxies (EIGs) are critical to our understanding of exotic systems throughout cosmic time. These EIGs exhibit spectral features requiring >54.42 eV photons: the energy needed to fully ionize…

The discovery of the high-ionization [Ne V] 3426A emission line in the spectrum of the blue compact dwarf (BCD) galaxy Tol 1214-277 is reported. The detection of this line implies the presence of intense ionizing X-ray emission with a…

We present JADES JWST/NIRSpec spectroscopy of GN-z11, the most luminous candidate $z>10$ Lyman break galaxy in the GOODS-North field with $M_{UV}=-21.5$. We derive a redshift of $z=10.603$ (lower than previous determinations) based on…

We report the detection of extended (>0.5-1kpc) high-ionization [MgIV] 4.487 $\mu$m (80 eV) emission in four local luminous infrared galaxies observed with JWST/NIRSpec. Excluding the nucleus and outflow of the Type 1 active galactic…