The Infrared Medium-deep Survey. III. Survey of Luminous Quasars at 4.7 ≤ z ≤ 5.4*

Jeon, Yiseul; Im, Myungshin; Kim, Dohyeong; Kim, Yong-Jung; Jun, Hyunsung D.; Pak, Soojong; Taak, Yoon Chan; Baek, Giseon; Choi, Changsu; Choi, Nahyun; Hong, Jisoo; Hyun, Minhee; Ji, Tae-Geun; Karouzos, Marios; Kim, Duho; Kim, Jae-Woo; Kim, Ji Hoon; Kim, Minjin; Kim, Sanghyuk; Lee, Hye-In; Lee, Seong-Kook; Park, Won-Kee; Park, Woojin; Yoon, Yongmin

doi:10.3847/1538-4365/aa7de5

Cited by 16 publications

(11 citation statements)

References 78 publications

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“…Recently, this LoBAL QSO was investigated by Jeon et al (2017), where their measurements of the luminosity and BH mass are consistent with those from Yi et al (2017). As the quality of near-IR spectra obtained by the Magellan telescope (see Jeon et al 2017) is much higher than that from Yi et al (2017), we use their near-IR spectra (in private communication) for J0122+1216 in this work.…”

Section: Compilation Of Optical Datamentioning

confidence: 99%

“…Notes on individual objects J0122+1216 was discovered as a quasar using the Lijiang 2.4-m Telescope (Yi et al 2015) in optical spectroscopy; later, it was further identified as a LoBAL QSO at z = 4.82 using near-IR spectroscopy (Yi et al 2017). Recently, this LoBAL QSO was investigated by Jeon et al (2017), where their measurements of the luminosity and BH mass are consistent with those from Yi et al (2017). As the quality of near-IR spectra obtained by the Magellan telescope (see Jeon et al 2017) is much higher than that from Yi et al (2017), we use their near-IR spectra (in private communication) for J0122+1216 in this work.…”

Section: Compilation Of Optical Datamentioning

confidence: 99%

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Spectroscopy of Broad Absorption Line Quasars at 3 ≲ Z ≲ 5. I. Evidence for Quasar Winds Shaping Broad/Narrow Emission Line Regions

Zuo

Yang

et al. 2020

ApJ

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We present an observational study of 22 broad absorption line quasars (BAL QSOs) at 3 z 5 based on optical/near-IR spectroscopy, aiming to investigate quasar winds and their effects. The near-IR spectroscopy covers the Hβ and/or Mg ii broad emission lines (BELs) for these quasars, allowing us to estimate their central black hole (BH) masses in a robust way. We found that our BAL QSOs on average do not have a higher Eddington ratio than that from non-BAL QSOs matched in redshift and/or luminosity. In a subset consisting of seven strong BAL QSOs possessing subrelativistic BAL outflows, we see the prevalence of large C iv-BEL blueshift (∼3100 km s −1 ) and weak [O iii] emission (particularly the narrow [O iii]λ5007 component), indicative of nuclear outflows affecting the narrow emission-line (NEL) regions. In another subset consisting of thirteen BAL QSOs having simultaneous observations of Mg ii and Hβ, we found a strong correlation between 3000Å and 5000Å monochromatic luminosity, consistent with that from non-BAL QSOs matched in redshift and luminosity; however, there is no correlation between Mg ii and Hβ in FWHM, likely due to nuclear outflows influencing the BEL regions. Our spectroscopic investigations offer strong evidence that the presence of nuclear outflows plays an important role in shaping the BEL/NEL regions of these quasars and possibly, regulating the growth of central supermassive black holes (SMBHs). We propose that BEL blueshift and BAL could be different manifestations of the same outflow system viewed at different sightlines and/or phases.

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Section: Compilation Of Optical Datamentioning

confidence: 99%

Section: Compilation Of Optical Datamentioning

confidence: 99%

Spectroscopy of Broad Absorption Line Quasars at 3 ≲ Z ≲ 5. I. Evidence for Quasar Winds Shaping Broad/Narrow Emission Line Regions

Zuo

Yang

et al. 2020

ApJ

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“…Based on wide-field surveys, half million quasars have hitherto been discovered (e.g., Pâris et al 2017), hun- Matsuoka et al 2016;Jeon et al 2017;Yang et al 2016Yang et al , 2017Wang et al 2016;Reed et al 2017). With the identification of high redshift quasars, we are now broadening our horizon of knowledge deep into the very early universe, especially on the cosmic re-ionization epoch.…”

Section: Introductionmentioning

confidence: 99%

The Infrared Medium-deep Survey. VI. Discovery of Faint Quasars at z ∼ 5 with a Medium-band-based Approach

Kim

Jeon

et al. 2019

ApJ

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The faint quasars with M 1450 > −24 mag are known to hold the key to the determination of the ultraviolet emissivity for the cosmic re-ionization. But only a few have been identified so far because of the limitations on the survey data. Here, we present the first results of the z ∼ 5 faint quasar survey with the Infrared Medium-deep Survey (IMS), which covers ∼ 100 deg 2 areas in J-band to the depths of J AB ∼ 23 mag. To improve selection methods, the medium-band follow-up imaging has been carried out using the SED camera for QUasars in Early uNiverse (SQUEAN) on the Otto Struve 2.1 m Telescope. The optical spectra of the candidates were obtained with 8-m class telescopes. We newly discovered 10 quasars with −25 < M 1450 < −23 at z ∼ 5, among which three have been missed in a previous survey using the same optical data over the same area, implying the necessity for improvements in high redshift faint quasars selection. We derived photometric redshifts from the medium-band data, and find that they have high accuracies of |∆z|/(1 + z) = 0.016. The mediumband-based approach allows us to rule out many of the interlopers that contaminate 20 % of the broad-band-selected quasar candidates. These results suggest that the medium-band-based approach is a powerful way to identify z ∼ 5 quasars and measure their redshifts at high accuracy (1-2 %). It is also a cost-effective way to understand the contribution of quasars to the cosmic re-ionization history. dreds of them being at high redshift of z 5 (Fan et al.1 The medium-band filters are named as m (initial of the medium-band) + the central wavelength of the filter in nm.

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“…Given the spectral shape and the escape fraction of LyC photons of quasars, the contribution of quasars to the hydrogen reionizing photons can be calculated from the quasar luminosity function (LF). Therefore, many observational studies have tried to determine the LF of quasars at z > 4 (Barger et al 2003;Fan et al 2006;Jiang et al 2008;Willott et al 2010;McGreer et al 2013;Bañaods et al 2016;Yang et al 2016;Jeon et al 2017;Kim et al 2019).…”

Section: Introductionmentioning

confidence: 99%

The Infrared Medium-deep Survey. \Romannum{7}. Faint Quasars at $z \sim 5$ in the ELAIS-N1 Field

Shin,

Im,

Kim

et al. 2020

Preprint

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The intergalactic medium (IGM) at z ∼ 5 to 6 is largely ionized, and yet the main source for the IGM ionization in the early universe is uncertain. Of the possible contributors are faint quasars with −26 M 1450 −23, but their number density is poorly constrained at z ∼ 5. In this paper, we present our survey of faint quasars at z ∼ 5 in the European Large-Area ISO Survey-North 1 (ELAIS-N1) field over a survey area of 6.51 deg 2 and examine if such quasars can be the dominant source of the IGM ionization. We use the deep optical/near-infrared data of the ELAIS-N1 field as well as the additional medium-band observations to find z ∼ 5 quasars through a two-step approach using the broadband color selection, and SED fitting with the medium-band information included. Adopting Bayesian information criterion, we identify ten promising quasar candidates. Spectra of three of the candidates are obtained, confirming all of them to be quasars at z ∼ 5 and supporting the reliability of the quasar selection. Using the promising candidates, we derive the z ∼ 5 quasar luminosity function at −26 M 1450 −23. The number density of faint z ∼ 5 quasars in the ELAIS-N1 field is consistent with several previous results that quasars are not the main contributors to the IGM-ionizing photons at z ∼ 5.

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The Infrared Medium-deep Survey. III. Survey of Luminous Quasars at 4.7 ≤ z ≤ 5.4*

Cited by 16 publications

References 78 publications

Spectroscopy of Broad Absorption Line Quasars at 3 ≲ Z ≲ 5. I. Evidence for Quasar Winds Shaping Broad/Narrow Emission Line Regions

Spectroscopy of Broad Absorption Line Quasars at 3 ≲ Z ≲ 5. I. Evidence for Quasar Winds Shaping Broad/Narrow Emission Line Regions

The Infrared Medium-deep Survey. VI. Discovery of Faint Quasars at z ∼ 5 with a Medium-band-based Approach

The Infrared Medium-deep Survey. \Romannum{7}. Faint Quasars at $z \sim 5$ in the ELAIS-N1 Field

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