Galaxy emission line classification using 3D line ratio diagrams
read the original abstract
Two-dimensional (2D) line ratio diagnostic diagrams have become a key tool in understanding the excitation mechanisms of galaxies. The curves used to separate the different regions - HII-like or else excited by an active galactic nucleus (AGN) - have been refined over time but the core technique has not evolved significantly. However, the classification of galaxies based on their emission line ratios really is a multi-dimensional problem. Here we exploit recent software developments to explore the potential of three-dimensional (3D) line ratio diagnostic diagrams. We introduce a specific set of 3D diagrams, the ZQE diagrams, which separate the oxygen abundance and the ionisation parameter of HII region-like spectra, and which also enable us to probe the excitation mechanism of the gas. By examining these new 3D spaces interactively, we define a new set of 2D diagnostics, the ZE diagnostics, which can provide the metallicity of objects excited by hot young stars, and which cleanly separate HII region-like objects from the different classes of AGNs. We show that these ZE diagnostics are consistent with the key log[NII]/H$\alpha$ vs. log[OIII]/H$\beta$ diagnostic currently used by the community. They also have the advantage of attaching a probability that a given object belongs to one class or to the other. Finally, we discuss briefly why ZQE diagrams can provide a new way to differentiate and study the different classes of AGNs in anticipation of a dedicated follow-up study.
This paper has not been read by Pith yet.
Forward citations
Cited by 13 Pith papers
-
Massive Galaxies Form Early and Gray: Stellar Assembly and Dust Attenuation at $\mathbf{z>3.5}$ from CAPERS
Massive galaxies at z>3.5 assembled stars earlier than theoretical models predict and exhibit gray dust attenuation, especially at the highest masses.
-
Empirical estimates of how massive galaxies can be in {\Lambda}CDM
Corrected empirical limits show the most massive galaxies never exceed the theoretical baryonic maximum of 0.16 times halo virial mass, keeping observations consistent with LambdaCDM at all redshifts.
-
Evolution of compressed clouds formed by filament coalescence. I. Oblique collisions
Oblique filament collisions lead to gravitational collapse of the compressed cloud when post-collision |gravitational energy| exceeds kinetic plus thermal plus magnetic energies, with lower angles and lower velocities...
-
BISTRO Survey: Gravity-Dominated and Magnetically Regulated Star Formation in M17 SW
High-resolution magnetic field maps of M17 SW reveal gravity-dominated energy budget with magnetic fields regulating collapse and accretion channels in a near-equipartition state.
-
Precise and Rapid Parameter Inference of Kilonova with Conditional Variational Autoencoder
A conditional variational autoencoder is trained on public kilonova light curves to enable rapid parameter inference for binary neutron star merger models in under three hours total.
-
On the Nature of Candle-Flame-Shaped Solar Flares and Sub-Alfv\'enic Supra-Arcade Plasma Downflows
3D MHD modeling reveals Y-points do not coincide with cusp tips in candle-flame flares and apparent downflow speeds underestimate Alfvén speeds by 2-10x due to projection effects.
-
The ${}^{13}\mathrm{CO}(2{-}1)/^{12}\mathrm{CO}(2{-}1)$ Line Ratio from 100 Molecular Clouds in the Large Magellanic Cloud
Observational study of 100 LMC GMCs finds median 13CO(2-1)/12CO(2-1) line ratio of 0.078, nearly linear with luminosity, and higher in clouds hosting IR-bright young stellar objects.
-
Empirical estimates of how massive galaxies can be in {\Lambda}CDM
Empirical upper limits on galaxy stellar masses from extreme value statistics, after correcting for Eddington bias and halo mass scatter, remain below the theoretical baryonic maximum of 0.16 times halo mass at all re...
-
Taking Inventory of the Most Promising Lensed Radio Sources for Constraining Fundamental Properties of Dark Matter
Reports results from two searches for new radio lenses in existing surveys and discusses the completeness of the population usable for constraining dark matter properties via astrometric perturbations.
-
PEARLS: JWST Counterparts of Micro-Jy Radio Sources in the NEP Time Domain Field. II. All Four Spokes
JWST finds infrared counterparts for nearly all micro-Jy radio sources, with star formation explaining the radio output in roughly 79% of cases after accounting for non-linear luminosity relations.
-
A 14-year-old Mystery: The Peculiar Case of the Engine-driven SN 2012ap
Late-time radio rebrightening in SN 2012ap is consistent with either progenitor mass-loss variation producing a density enhancement or an off-axis energetic jet viewed at large angle, potentially reclassifying it as G...
-
COOL-LAMPS IX: A Rare Duo of Quasars Each Lensed by a Single Massive Galaxy Cluster
A single galaxy cluster lenses two quasars (one Type I at z=1.524, one dust-obscured Type II at z=1.939) into four images each, yielding a projected mass of ~3.3e14 solar masses within 500 kpc and time delays of hundr...
-
Comparative Analysis of EMCEE, Gaussian Process, and Masked Autoregressive Flow in Constraining the Hubble Constant Using Cosmic Chronometers Dataset
EMCEE outperforms GP and MAF in recovering true H0 from mock cosmic chronometer datasets, with GP most sensitive to data points via delete-d jackknife analysis.
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.