Theoretical Evolution of Optical Strong Lines Across Cosmic Time

Kewley, Lisa J.; Dopita, Michael A.; Leitherer, Claus; Davé, Romeel; Yuan, Tiantian; Allen, M. G.; Groves, Brent; Sutherland, Ralph S.

doi:10.1088/0004-637x/774/2/100

Cited by 427 publications

(629 citation statements)

References 162 publications

(237 reference statements)

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“…These lines show the range of line ratios expected for galaxies at z = 1.5 with intense star formation typical for galaxies at these redshifts, and AGN with metal-poor narrow line regions and a metal enrichment history predicted by cosmological models of galaxy evolution (Davé et al 2011). These conditions are referred to as "model 4" by Kewley et al (2013). J-band spectroscopy would be required to investigate whether TXS 2355-003 falls onto the low-redshift AGN branch or above.…”

Section: Line Diagnosticsmentioning

confidence: 86%

Defying jet-gas alignment in two radio galaxies atz~ 2 with extended light profiles: Similarities to brightest cluster galaxies

Collet

Nesvadba

Breuck

et al. 2015

A&A

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We report the detection of extended warm ionized gas in two powerful high-redshift radio galaxies, NVSS J210626-314003 at z = 2.10 and TXS 2353-003 at z = 1.49, that does not appear to be associated with the radio jets. This is contrary to what would be expected from the alignment effect, a characteristic feature of distant, powerful radio galaxies at z ≥ 0.6. The gas also has smaller velocity gradients and line widths than most other high-z radio galaxies with similar data. Both galaxies are part of a systematic study of 50 high-redshift radio galaxies with SINFONI, and are the only two that are characterized by the presence of high surface-brightness gas not associated with the jet axis and by the absence of such gas aligned with the jet. Both galaxies are spatially resolved with ISAAC broadband imaging covering the rest-frame R band, and have extended wings that cannot be attributed to line contamination. We argue that the gas and stellar properties of these galaxies are more akin to gas-rich brightest cluster galaxies in cool-core clusters than the general population of high-redshift radio galaxies at z > ∼ 2. In support of this interpretation, one of our sources, TXS 2353-003, for which we have Hα narrowband imaging, is associated with an overdensity of candidate Hα emitters by a factor of ∼8 relative to the field at z = 1.5. We discuss possible scenarios of the evolutionary state of these galaxies and the nature of their emission line gas within the context of cyclical AGN feedback.

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Section: Line Diagnosticsmentioning

confidence: 86%

Defying jet-gas alignment in two radio galaxies atz~ 2 with extended light profiles: Similarities to brightest cluster galaxies

Collet

Nesvadba

Breuck

et al. 2015

A&A

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“…Because the [N II] emission lines are not observed in 3 galaxies of ID-6, ID-8, and ID-10, we only plot the other 8 galaxies here. These 8 galaxies are located in or near the SFG region that is defined by the models of starbursts at z = 2 (Kewley et al 2013a). Although ID-3 is located on the edge of the SFG and AGN regions, the rest-frame UV and optical spectra of ID-3 show no signatures of an AGN (Steidel et al 2014).…”

Section: Agn Activitymentioning

confidence: 99%

“…Photoionization models suggest that the BPT offsets appear, if, at least, one of the four parameters is changed from values of typical local galaxies (e.g. Kewley et al 2013a;Steidel et al 2014;Sanders et al 2016).…”

Section: Introductionmentioning

confidence: 99%

Evolution of N/O abundance ratios and ionization parameters from z ∼ 0 to 2 investigated by the direct temperature method

Kojima

Ouchi

Nakajima

et al. 2017

Publications of the Astronomical Society of Japan

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We present N/O abundance ratios, ionization parameters q ion , and oxygen abundance O/H for a total of 41 galaxies (11 individual galaxies and a 30-galaxy stack) including Lyα emitters and Lyman break galaxies at z ∼ 2, and investigate galaxy evolution from z ∼ 0 to 2 in conjunction with 208,529 local SDSS galaxies and 9 green pea galaxies (GPs). In contrast with most of the recent studies, we obtain the N/O ratio, q ion , and O/H measurements by direct T e methods with [O III] λ4363 and O III] λ1665 lines. Based on these reliable measurements, we find that there exist z ∼ 2 galaxies with an excess of N/O falling beyond the local average of N/O-O/H relation, while the majority of the z ∼ 2 galaxies have the N/O ratios nearly comparable with z ∼ 0 galaxies in the N/O-stellar mass relation. Our galaxies place the upper limit of N/O ratio log(N/O) ≤ −1.26 on average, suggesting that the N/O ratio evolves, if at all, by < 0.17 dex. Exploiting our reliable measurements free from the N/O-q ion -O/H degeneracies, we identify, for the first time, that z ∼ 2 galaxies with offsets in the BPT diagram indicate either 1) only an N/O excess, 2) only a q ion excess, or 3) both N/O and q ion excesses. We argue that the BPT offsets at z ∼ 2 are not made by one of 1)-3) galaxy populations alone, but the composite of 1)-3) populations. We confirm that these 1)-3) populations also exist at z ∼ 0, such as GPs and SDSS low-mass and high-SFR galaxies (LMHSs).

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“…Alternatively, candidate narrow-lined AGNs at z0.5-1 can be identified based on signatures at other wavelengths (e.g., infrared color, infrared/optical colors, X-ray emission) and followedup with ground-based infrared spectroscopy to observe the traditional rest-frame BPT emission lines, where the cosmic BPT diagram can then differentiate between AGNs and star-forming galaxies (Kewley et al 2013a(Kewley et al , 2013bKartaltepe et al 2015).…”

Section: Identifying Type 2 Agnsmentioning

confidence: 99%

On R − W1 as a Diagnostic to Discover Obscured Active Galactic Nuclei in Wide-Area X-Ray Surveys

LaMassa

Civano

Brusa

et al. 2016

ApJ

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Capitalizing on the all-sky coverage of WISEand the 35% and 50% sky coverage from Sloan Digital Sky Survey and Pan-STARRS, respectively, we explore the efficacy of-, as a color diagnostic to identify obscured supermassive black hole accretion in wide-area X-ray surveys. We use the ∼16.5 deg 2 Stripe 82 X-ray survey data as a testbed to compare R W1 -with R−K, an oft-used obscured active galactic nucleus (AGN) selection criterion, and examine where different classes of objects lie in this parameter space. Most stars follow a well-defined path in R−K versus R W1space. We demonstrate that optically normal galaxies hosting X-ray AGNs at redshifts z 0.5 1 < < can be recovered with an R W1 4 -> colorcut, while they typically are not selected as AGNs based on their W W 1 2 -colors. Additionally, different observed X-ray luminosity bins favor different regions in R W1 -parameter space: moderate-luminosity AGNs > -erg s −1 ) have bluer colors; higher spectroscopic completeness of the Stripe 82X sample is needed to determine whether this is a selection effect or an intrinsic property. Finally, we parameterize X-ray obscuration of Stripe 82X AGNs by calculating their hardness ratios (HRs) and find no clear trends between HR and optical reddening. Our results will help inform best-effort practices in followingup obscured AGN candidates in current and future wide-area, shallow X-ray surveys, including the all-sky eROSITA mission.

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Theoretical Evolution of Optical Strong Lines Across Cosmic Time

Cited by 427 publications

References 162 publications

Defying jet-gas alignment in two radio galaxies atz~ 2 with extended light profiles: Similarities to brightest cluster galaxies

Defying jet-gas alignment in two radio galaxies atz~ 2 with extended light profiles: Similarities to brightest cluster galaxies

Evolution of N/O abundance ratios and ionization parameters from z ∼ 0 to 2 investigated by the direct temperature method

On R − W1 as a Diagnostic to Discover Obscured Active Galactic Nuclei in Wide-Area X-Ray Surveys

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