Fundamental differences in the properties of red and blue quasars: measuring the reddening and accretion properties with <i>X-shooter</i>

Fawcett, V. A.; Alexander, D. M.; Rosario, D. J.; Klindt, L.; Lusso, Elisabeta; Morabito, L. K.; Rivera, G. Calistro

doi:10.1093/mnras/stac945

Cited by 22 publications

(9 citation statements)

References 103 publications

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“…To provide a glimpse of the overall spectral diversity of targets in the QSO survey, in Figure 13 we plot the DESI spectra for individual QSOs, selected to cover a broad range in spectral diversity. 55 Each composite spectrum is constructed following the approach outlined in Fawcett et al (2022). Briefly, the ends of each contributing spectrum are trimmed to remove noisy data and then corrected for Galactic extinction and shifted to rest-frame wavelengths using the VI redshift.…”

Section: A Glimpse Of the Spectral Diversity In The Qso Surveymentioning

confidence: 99%

The DESI Survey Validation: Results from Visual Inspection of the Quasar Survey Spectra

Alexander

Davis

Chaussidon

et al. 2023

Self Cite

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A key component of the Dark Energy Spectroscopic Instrument (DESI) survey validation (SV) is a detailed visual inspection (VI) of the optical spectroscopic data to quantify key survey metrics. In this paper we present results from VI of the quasar survey using deep coadded SV spectra. We show that the majority (≈70%) of the main-survey targets are spectroscopically confirmed as quasars, with ≈16% galaxies, ≈6% stars, and ≈8% low-quality spectra lacking reliable features. A nonnegligible fraction of the quasars are misidentified by the standard spectroscopic pipeline, but we show that the majority can be recovered using post-pipeline “afterburner” quasar-identification approaches. We combine these “afterburners” with our standard pipeline to create a modified pipeline to increase the overall quasar yield. At the depth of the main DESI survey, both pipelines achieve a good-redshift purity (reliable redshifts measured within 3000 km s−1) of ≈99%; however, the modified pipeline recovers ≈94% of the visually inspected quasars, as compared to ≈86% from the standard pipeline. We demonstrate that both pipelines achieve a median redshift precision and accuracy of ≈100 km s−1 and ≈70 km s−1, respectively. We constructed composite spectra to investigate why some quasars are missed by the standard pipeline and find that they are more host-galaxy dominated (i.e., distant analogs of “Seyfert galaxies”) and/or more dust reddened than the standard-pipeline quasars. We also show example spectra to demonstrate the overall diversity of the DESI quasar sample and provide strong-lensing candidates where two targets contribute to a single spectrum.

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Section: A Glimpse Of the Spectral Diversity In The Qso Surveymentioning

confidence: 99%

The DESI Survey Validation: Results from Visual Inspection of the Quasar Survey Spectra

Alexander

Davis

Chaussidon

et al. 2023

Self Cite

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“…Indeed, the strong UV/X-ray radiation of WLQs and super-Eddington NLS1s can trigger a powerful disk wind, which may have a clumpy nature and cover a wide viewing angle (e.g., Ohsuga & Mineshige 2011;Takeuchi et al 2014;Hagino et al 2016). This clumpy wind offers a natural explanation for the drastic X-ray variability observed in both WLQs and WLQ-like Seyferts (Miniutti et al 2012;Reeves et al 2020;Jin et al 2022b) and the statistical transition of red quasars evolving into blue quasars (Temple et al 2019;Fawcett et al 2022), as well as the transformation of broad absorption lines observed recently in some WLQs (Yi et al 2019(Yi et al , 2022. Then, the observations of the two WLQ-like Seyferts with totally different reddening values support the idea that a similar disk wind scenario is applicable for both WLQs and WLQ-like Seyferts (Jin et al 2022a), although their black hole masses differ by more than one order of magnitude.…”

Section: Emission Line Spectrummentioning

confidence: 99%

Discovery of a Radio-loud Narrow-line Seyfert 1 Galaxy at z = 0.9 Reddened with a Strong 2175 Å Bump

Zhou

Hao

Jiang

et al. 2022

ApJ

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We present a broadband spectrophotometric analysis of an unusual quasar, SDSS J160558.86+474300.1, at z = 0.9, found in a systematic search for reddened radio-loud narrow-line Seyfert 1 galaxies (NLS1s). J1605+4743 qualifies for the conventional definition of an NLS1 in its permitted emission line widths and Hβ/[O iii] flux ratio. It also shows strong Fe ii emissions. J1605+4743 has a steep radio spectrum. With a radio loudness of ∼150 (70) before (after) reddening correction, it is among the most radio-loud NLS1s discovered. In addition, the blueshifted emission lines are also found to be weak, suggesting that it can be an exotic “wind-dominated” Seyfert similar to weak-line quasars, especially the ones with strong reddening. As an extreme hybrid central engine, its environment and host galaxy become rather intriguing. We discover in it a proximate 2175 Å absorber with a bump strength similar to the average value of 2175 Å absorbers in the Milky Way, which we suspect can be intrinsic to the quasar. In addition, the quasar seems to have enhanced instead of suppressed star formation at a rate of ≳94 M ⊙ yr−1. The combination of these unusual properties, i.e., the unique extinction, strong Fe ii and [O ii] lines, weak [O iii], Mg ii, and Balmer lines, and large radio loudness, might hold important clues to accretion physics, the formation/destruction of dust grains in the environment of active galactic nuclei, and possibly also the coevolution of supermassive black holes and their host galaxies in general.

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“…12. 8 8 Each composite spectrum is constructed following the approach outlined in Fawcett et al (2022). Briefly, the ends of each contributing spectrum are trimmed to remove noisy data and then corrected for Galactic extinction and shifted to rest-frame wavelengths using the VI redshift.…”

Section: Investigating the Differences Between The Redrock Quasars An...mentioning

confidence: 99%

The DESI Survey Validation: Results from Visual Inspection of the Quasar Survey Spectra

Alexander,

Davis,

Chaussidon

et al. 2022

Preprint

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A key component of the Dark Energy Spectroscopic Instrument (DESI) survey validation (SV) is a detailed visual inspection (VI) of the optical spectroscopic data to quantify key survey metrics. In this paper we present results from VI of the quasar survey using deep coadded SV spectra. We show that the majority (≈ 70%) of the main-survey targets are spectroscopically confirmed as quasars, with ≈ 16% galaxies, ≈ 6% stars, and ≈ 8% low-quality spectra lacking reliable features. A nonnegligible fraction of the quasars are misidentified by the standard DESI spectroscopic pipeline but we show that the majority can be recovered using post-pipeline "afterburner" quasar-identification approaches. We combine these "afterburners" with our standard pipeline to create a modified pipeline to improve the overall quasar completeness. At the depth of the main DESI survey both pipelines achieve a good-redshift purity (reliable redshifts measured within 3000 km s −1 ) of ≈ 99%; however, the modified pipeline recovers ≈ 94% of the visually inspected quasars, as compared to just ≈ 86% from the standard pipeline. We demonstrate that both pipelines achieve an overall redshift precision and accuracy of ≈ 100 km s −1 and ≈ 70 km s −1 , respectively. We constructed composite spectra to investigate why some quasars are missed by the standard spectroscopic pipeline and find that they are more host-galaxy dominated and/or dust reddened than the standard-pipeline quasars. We also show example spectra to demonstrate the overall diversity of the DESI quasar sample and provide strong-lensing candidates where two targets contribute to a single DESI spectrum.

show abstract

Fundamental differences in the properties of red and blue quasars: measuring the reddening and accretion properties with X-shooter

Cited by 22 publications

References 103 publications

The DESI Survey Validation: Results from Visual Inspection of the Quasar Survey Spectra

The DESI Survey Validation: Results from Visual Inspection of the Quasar Survey Spectra

Discovery of a Radio-loud Narrow-line Seyfert 1 Galaxy at z = 0.9 Reddened with a Strong 2175 Å Bump

The DESI Survey Validation: Results from Visual Inspection of the Quasar Survey Spectra

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