The broadband spectral energy distributions of SDSS blazars

Li, Huai-Zhen; Chen, Luo-En; Jiang, Yunguo; Yi, Ting-Feng

doi:10.1088/1674-4527/15/7/001

Cited by 5 publications

(3 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We also found that the slopes of correlations for TeV HSP BLs are similar to those for non-TeV HSP BLs, and the log νL γ vs log νL R correlation is strongest. The strong γray vs radio correlation was also discussed by other authors (Dondi & Ghisellini 1995;Muecke et al 1997;Xie et al 1997;Zhou et al 1997;Fan et al 1998Fan et al , 2012Fan et al , 2015Fan et al , 2016Cheng et al 2000;Yang & Fan 2005;Giroletti et al 2010Giroletti et al , 2012Pushkarev et al 2010;Linford et al 2011;Yang et al 2012bYang et al ,a, 2014Li et al 2015).…”

Section: Correlationssupporting

confidence: 57%

Comparison between TeV and non-TeV BL Lac Objects

Lin

Fan

2016

Res. Astron. Astrophys.

View full text Add to dashboard Cite

BL Lacertae objects (BL Lacs) is the dominant population of TeV emitting blazars. In this work, we investigate whether there is any special observational properties for TeV sources. To do so, we will compare the observational properties of TeV detected BL Lacs (TeV BLs) and non-TeV detected BL Lac objects (non-TeV BLs). From the 3rd F ermi/LAT catalog (3FGL), we can get 662 BL Lacs, out of which, 47 are TeV BLs and 615 are non-TeV BLs. Their multi-wavelength flux densities (F R , F O , F X , F γ ), photon spectral indexes (α ph X , α ph γ ), and effective spectral indexes (α RO and α OX ) are compiled from the available literatures. Then the luminosities (log νL R , log νL O , log νL X , log νL γ ) are calculated. From comparisons, we found that TeV BLs are different from low-synchrotron-peaked BLs (LSP) and intermediate-synchrotron-peaked BLs (ISP), but TeV BLs show similar properties as high-synchrotron-peaked BLs (HSP). Therefore, we concentrated on comparison between TeV HSP BLs and non-TeV HSP BLs. Analysis results suggest that TeV HSP BLs and non-TeV HSP BLs show some differences in their α RO and α ph γ , while their other properties are quite similar.

show abstract

Section: Correlationssupporting

confidence: 57%

Comparison between TeV and non-TeV BL Lac Objects

Lin

Fan

2016

Res. Astron. Astrophys.

View full text Add to dashboard Cite

show abstract

“…Odo and Aroh 2020). Li et al (2015) earlier argued that the αro − z correlation using SDSS data provides more evidence for the unified scheme as proposed by Fossati et al (1998).…”

Section: Discussionmentioning

confidence: 91%

Spectral Properties of Fermi Blazars and their Unification Schemes

et al. 2020

View full text Add to dashboard Cite

We use the distributions of spectral indices (αv ) of a large homogenous sample of Fermi-detected blazars to re-investigate the relationship between flat spectrum radio quasars (FSRQs) and subclasses of BL Lac objects (BL Lacs). We compute the broadband synchrotron and Compton spectral indices from radio-to-X-ray and X-ray to y-ray bands, respectively. Analyses of our data show continuity in the distributions of the spectral indices from FSRQs to HSP through LSP and ISP subclasses of BL Lacs. We find from y-ray luminosity distribution that the jetted radio galaxies form the low-luminosity tail of the distribution, which is suggestive that the sequence can be extended to the young jetted galaxy populations. We observe a significant difference in the shape of Compton and synchrotron spectra: significant anti-correlation (r ∼−0.80) exists between the broadband Compton and synchrotron spectral indices. Furthermore, the broadband spectral indices vary significantly with redshift (z) at low redshift (z < 0.3) and remain fairly constant at high (z ≥ 0.3) redshift. The trend of the variations suggests a form of evolutionary connection between subclasses of blazars. Thus, while selection effect may be significant at low redshift, evolutionary sequence can also be important. Our results are not only consistent with a unified scheme for blazars and their young jetted galaxy counterparts but also suggest that the broadband spectral sequence of blazars is not a secondary effect of redshift dependence.

show abstract

“…Other possible effects that could affect our intrinsic quasar photometry model would be systematic variations in the emission lines, e.g., the Baldwin effect (Baldwin 1977), blazars with no apparent emission lines, or quasars with abnormal spectral shapes (Meusinger et al 2012). However, as blazars and quasars with abnormal spectral shapes contribute very little to the overall population of quasars (Meusinger et al 2012;Li et al 2015), we have neglected the contribution of these in order to keep the model as simple as possible.…”

Section: Simulating Quasar Photometrymentioning

confidence: 99%

The effect of dust bias on the census of neutral gas and metals in the high-redshift Universe due to SDSS-II quasar colour selection

Krogager

Fynbo

Møller

et al. 2019

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

We present a systematic study of the impact of a dust bias on samples of damped Lyman-α absorbers (DLAs). This bias arises as an effect of the magnitude and colour criteria utilized in the Sloan Digital Sky Survey (SDSS) quasar target selection up until data release 7 (DR7). The bias has previously been quantified assuming only a contribution from the dust obscuration. In this work, we apply the full set of magnitude and colour criteria used up until SDSS DR7 in order to quantify the full impact of dust biasing against dusty and metal-rich DLAs. We apply the quasar target selection algorithm on a modelled population of intrinsic colours, and by exploring the parameter space consisting of redshift, (z qso and z abs ), optical extinction, and H i column density, we demonstrate how the selection probability depends on these variables. We quantify the dust bias on the following properties derived for DLAs at z ≈ 3: the incidence rate, the mass density of neutral hydrogen and metals, the average metallicity. We find that all quantities are significantly affected. When considering all uncertainties, the mass density of neutral hydrogen is underestimated by 10 to 50%, and the mass density in metals is underestimated by 30 to 200%. Lastly, we find that the bias depends on redshift. At redshift z = 2.2, the mass density of neutral hydrogen and metals might be underestimated by up to a factor of 2 and 5, respectively. Characterizing such a bias is crucial in order to accurately interpret and model the properties and metallicity evolution of absorption-selected galaxies.

show abstract

The broadband spectral energy distributions of SDSS blazars

Cited by 5 publications

References 47 publications

Comparison between TeV and non-TeV BL Lac Objects

Comparison between TeV and non-TeV BL Lac Objects

Spectral Properties of Fermi Blazars and their Unification Schemes

The effect of dust bias on the census of neutral gas and metals in the high-redshift Universe due to SDSS-II quasar colour selection

Contact Info

Product

Resources

About