SDSS J094533.99+100950.1 - the remarkable weak emission line quasar

Hryniewicz, Krzysztof; Czerny, B.; Nikołajuk, M.; Kuraszkiewicz, Joanna

doi:10.1111/j.1365-2966.2010.16418.x

Cited by 52 publications

(103 citation statements)

References 63 publications

(99 reference statements)

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“…Instead, S06 proposed that WLQs are either the long-sought, high-redshift counterparts to BL Lacertae (BL Lac) objects (e.g., Stocke & Perrenod 1981) or that they are "ordinary" unbeamed, unobscured quasars with extreme properties such as a deficit of line-emitting gas in the broad emission line region (BELR) or an extremely high accretion rate (see also Fan et al 1999). It has also been speculated that WLQs may represent an early or transitional phase in quasar evolution where quasar activity just recently "switched on" (Hryniewicz et al 2010; see also Liu & Zhang 2011).…”

Section: Introductionmentioning

confidence: 99%

“…The discovery of WLQs only at z 2.2 is clearly a selection effect, as the onset of the Lyα forest emerges in the SDSS spectral range at that redshift. Indeed, there are indications for a population of lower-redshift sources with similar characteristics to the high-redshift WLQ population (e.g., McDowell et al 1995;Leighly et al 2007b;Hryniewicz et al 2010, Plotkin et al 2010b.…”

Section: Introductionmentioning

confidence: 99%

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The Ultraviolet-to-Mid-Infrared Spectral Energy Distribution of Weak Emission Line Quasars

Lane

Shemmer

Diamond‐Stanic

et al. 2011

ApJ

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We present Spitzer Space Telescope photometry of 18 Sloan Digital Sky Survey (SDSS) quasars at 2.7 z 5.9 which have weak or undetectable high-ionization emission lines in their rest-frame ultraviolet (UV) spectra (hereafter weak-lined quasars, or WLQs). The Spitzer data are combined with SDSS spectra and ground-based, near-infrared (IR) photometry of these sources to produce a large inventory of spectral energy distributions (SEDs) of WLQs across the rest-frame ∼0.1-5 μm spectral band. The SEDs of our sources are inconsistent with those of BL Lacertae objects which are dominated by synchrotron emission due to a jet aligned close to our line of sight, but are consistent with the SED of ordinary quasars with similar luminosities and redshifts that exhibit a near-to-mid-IR "bump," characteristic of hot dust emission. This indicates that broad emission lines in WLQs are intrinsically weak, rather than suffering continuum dilution from a jet, and that such sources cannot be selected efficiently from traditional photometric surveys.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The Ultraviolet-to-Mid-Infrared Spectral Energy Distribution of Weak Emission Line Quasars

Lane

Shemmer

Diamond‐Stanic

et al. 2011

ApJ

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“…An unexpected population of ∼10 2 quasars were discovered within the spectra of the Sloan Digital Sky Survey (SDSS; York et al 2000) that display exceptionally weak or completely missing broad emission lines in the ultraviolet (UV) rest-frame (Fan et al 1999;Anderson et al 2001;Collinge et al 2005;Diamond-Stanic et al 2009, hereafter DS09;Plotkin et al 2010a, hereafter P10;Hryniewicz et al 2010;Wu et al 2011;Meusinger & Balafkan 2014). The first systematic search for such weak emission line quasars (WLQs) was performed by DS09, who examined the rest-frame equivalent width (W r ) distribution of the Lyα λ1216+N V λ1240 blend for SDSS quasars at z > 3.…”

Section: Introductionmentioning

confidence: 99%

Detection of Rest-Frame Optical Lines From X-Shooter Spectroscopy of Weak Emission-Line Quasars

Plotkin

Shemmer

Trakhtenbrot

et al. 2015

ApJ

104

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Over the past 15 years, examples of exotic radio-quiet quasars with intrinsically weak or absent broad emission line regions (BELRs) have emerged from large-scale spectroscopic sky surveys. Here, we present spectroscopy of seven such weak emission line quasars (WLQs) at moderate redshifts (z = 1.4 − 1.7) using the X-shooter spectrograph, which provides simultaneous optical and nearinfrared spectroscopy covering the rest-frame ultraviolet through optical. These new observations effectively double the number of WLQs with spectroscopy in the optical rest-frame, and they allow us to compare the strengths of (weak) high-ionization emission lines (e.g., C IV) to low-ionization lines (e.g., Mg II, Hβ, Hα) in individual objects. We detect broad Hβ and Hα emission in all objects, and these lines are generally toward the weaker end of the distribution expected for typical quasars (e.g., Hβ has rest-frame equivalent widths ranging from 15-40Å.). However, these low-ionization lines are not exceptionally weak, as is the case for high-ionization lines in WLQs. The X-shooter spectra also display relatively strong optical Fe II emission, Hβ FWHM 4000 km s −1 , and significant C IV blueshifts (≈1000-5500 km s −1 ) relative to the systemic redshift; two spectra also show elevated ultraviolet Fe II emission, and an outflowing component to their (weak) Mg II emission lines. These properties suggest that WLQs are exotic versions of "wind-dominated" quasars. Their BELRs either have unusual high-ionization components, or their BELRs are in an atypical photoionization state because of an unusually soft continuum.

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“…The corresponding magnitude threshold is R ∼ 18.5 for the 2 m class telescopes we used. Seven radio-quiet BL Lac objects were selected from Plotkin et al (2010), and SDSS J094533.99+100950.1 was selected from A&A 576, A3 (2015) Hryniewicz et al (2010). The above selection criteria are similar to those in GJC2013 and CKG2014.…”

Section: Observations and Data Reductionmentioning

confidence: 99%

“…The UV/optical emission lines are absent in their UV/optical spectroscopies, though the shape and luminosity of their continua are comparable to the normal AGNs. The fraction of these special AGNs is small (∼1/1000) in the SDSS DR 7 sample; however, it could be an important stage in the evolving sequence of AGNs (Hryniewicz et al 2010;Liu & Zhang 2011). In the early stage of an active cycle of AGNs, the radiative feedback can expel the gas from broad line regions and result in weak or even in the disappearance of broad emission lines (Liu & Zhang 2011).…”

Section: Introductionmentioning

confidence: 99%

Intranight optical variability of radio-quiet BL Lacertae objects

Liu¹,

Zhang²,

Zhang³

2015

A&A

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Aims. Intranight variation (or microvariation) is a common phenomenon of radio-loud BL Lac objects. However, it is not clear whether the recently found radio-quiet BL Lac objects have the same properties. The occurrence rate of intranight variation is helpful in distinguishing the mechanism of the continuum of radio-quiet BL Lac objects. Methods. We conducted a photometric monitoring of 8 radio-quiet BL Lac objects by the Xinglong 2.16 m and Lijiang 2.4 m telescopes. The differential light curves are calculated between each target and two comparison stars. To quantify the variation, the significance of variation is examined by a scaled F-test. Results. No significant variation is found in the 11 sessions of light curves of 8 radio-quiet BL Lac objects (one galactic source is excluded). The lack of microvariation in radio-quiet BL Lac objects is consistent with the detection rate of microvariation in normal radio-quiet AGNs, but much lower than for radio-loud AGNs. This result indicates that the continua of the radio-quiet BL Lac objects are not dominated by jets that will induce frequent microvariations.

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SDSS J094533.99+100950.1 - the remarkable weak emission line quasar

Cited by 52 publications

References 63 publications

The Ultraviolet-to-Mid-Infrared Spectral Energy Distribution of Weak Emission Line Quasars

The Ultraviolet-to-Mid-Infrared Spectral Energy Distribution of Weak Emission Line Quasars

Detection of Rest-Frame Optical Lines From X-Shooter Spectroscopy of Weak Emission-Line Quasars

Intranight optical variability of radio-quiet BL Lacertae objects

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