Kuraszkiewicz, Joanna

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Kuraszkiewicz, Joanna

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Kuraszkiewicz

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Joanna

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Kuraszkiewicz, Joanna

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Principal Component Analysis of the Spectral Energy Distribution and Emission Line Properties of Red 2mass Active Galactic Nuclei
(IOP Publishing, 2009) Kuraszkiewicz, Joanna; Wilkes, Belinda; Schmidt, Gary; Smith, Paul S.; Cutri, Roc; Czerny, Bo?ena
We analyze the spectral energy distributions (SEDs) and emission-line properties of the red (J − KS > 2) 2MASS active galactic nuclei (AGNs) using principle component analysis (PCA). The sample includes 44 low redshift AGNs with low or moderate obscuration (NH < 1023 cm−2) as indicated by X-rays and SED modeling. The obscuration of the AGNs allows us to see weaker emission components (host-galaxy emission, AGN scattered light) which are usually outshone by the AGN. The first four eigenvectors explain 70% of the variance in the sample. Eigenvector 1 (33% variance in the sample) correlates with the ratios of the intrinsic X-ray flux to the observed optical/IR fluxes and the F(2–10 keV)/F([O iii]) ratio. We suggest that it is primarily driven by the L/LEdd ratio and strengthened by intrinsic absorption (both circumnuclear and galactic). Eigenvector 2 (18% of variance) correlates with optical/IR colors (B − KS, B − R, J − KS) and optical spectral type and depends on the contribution of the host galaxy relative to the observed AGN emission. Eigenvector 3 (12% of variance) correlates with reddening indicators obtained from the X-rays (hardness ratio, spectral index, NH ), and the narrow Hα/Hβ emission-line ratio. Their relation suggests a common absorber for the optical/X-rays lying outside the narrow-line region possibly in a moderately inclined host galaxy. Eigenvector 4 (8% of variance) correlates with the degree of polarization and the broad Hα/Hβ ratio, indicating that dust, which scatters the nuclear emission (continuum and the broad-line region emission), also reddens the broad lines. Our analysis shows that, although as suggested by unification schemes, the inclination dependent obscuration (circumnuclear and the host galaxy) is important in determining the AGN SEDs, the L/LEdd ratio is the most important factor, followed by host-galaxy emission.
The Spectral Energy Distributions of Red Two Micron All Sky Survey Active Galactic Nuclei
(IOP Publishing, 2009) Kuraszkiewicz, Joanna; Wilkes, Belinda; Schmidt, Gary; Ghosh, Himel; Smith, Paul S.; Cutri, Roc; Hines, Dean; Huff, Eric M.; McDowell, Jonathan; Nelson, Brant
We present infrared (IR) to X-ray spectral energy distributions (SEDs) for 44 red active galactic nuclei (AGNs) selected from the Two Micron All Sky Survey (2MASS) survey on the basis of their red J − KS color (> 2 mag) and later observed by Chandra. In comparison with optically-, radio-, and X-ray-selected AGNs, their median SEDs are red in the optical and near-IR (NIR) with little/no blue bump. Comparison of the various broadband luminosity ratios shows that the main differences lie at the blue end of the optical and in the NIR to far-IR ratios (when available), with the red 2MASS AGNs being redder than the other samples. It thus seems that NIR color selection isolates the reddest subset of AGNs that can be classified optically. The shape of the SEDs is generally consistent with modest absorption by gas (in the X-ray) and dust (in the optical–IR), as demonstrated by comparing the optical and NIR colors with a reddened median SED and observed optical+NIR to intrinsic X-ray ratios. The levels of obscuration, estimated from X-rays, far-IR, and our detailed optical/NIR color modeling, are all consistent implying NH few × 1022 cm−2. We present SED models that show how the AGN optical/NIR colors change due to differing amounts of reddening, AGN to host galaxy ratio, redshift, and scattered light emission, and apply them to the sources in the sample. We find that the 2MASS AGN optical color, B − R, and to a lesser extent the NIR color, J − KS, are strongly affected by reddening, host galaxy emission, redshift, and in few, highly polarized objects also by scattered AGN light (<2% of intrinsic AGN light in the R band is scattered; this contribution becomes significant as the direct AGN light is absorbed). The lack of low equivalent widths in the distribution of the [O iii] λ5007 emission line implies a predominance of inclined objects in the red 2MASS sample. The obscuration/ inclination of the AGN allows us to see weaker emission components which are generally swamped by the AGN.
Optical Spectroscopy of Type Ia Supernovae
(IOP Publishing, 2008) Matheson, T.; Kirshner, Robert; Challis, Peter; Jha, S.; Garnavich, P. M.; Berlind, Perry; Calkins, Michael; Blondin, S.; Balog, Z.; Bragg, A. E.; Caldwell, Nelson; Concannon, K. Dendy; Falco, E. E.; Graves, G. J. M.; Huchra, J. P.; Kuraszkiewicz, Joanna; Mader, J. A.; Mahdavi, A.; Phelps, Matthew; Rines, K.; Song, I.; Wilkes, Belinda
We present 432 low-dispersion optical spectra of 32 Type Ia supernovae (SNe Ia) that also have well-calibrated light curves. The coverage ranges from 6 epochs to 36 epochs of spectroscopy. Most of the data were obtained with the 1.5 m Tillinghast telescope at the F. L. Whipple Observatory with typical wavelength coverage of 3700-7400 Å and a resolution of ~7 Å. The earliest spectra are 13 days before B-band maximum; two-thirds of the SNe were observed before maximum brightness. Coverage for some SNe continues almost to the nebular phase. The consistency of the method of observation and the technique of reduction makes this an ideal data set for studying the spectroscopic diversity of SNe Ia.
[O II] Emission, Eigenvector 1, and Orientation in Radio-quiet Quasars
(IOP Publishing, 2000) Kuraszkiewicz, Joanna; Wilkes, Belinda; Brandt, W. N.; Vestergaard, M.
We present supportive evidence that the Boroson & Green eigenvector 1 is not driven by source orientation and further that both [O III] λ5007 and [O II] λ3727 are isotropically emitted in the radio-quiet sample of bright quasar survey (BQS) quasars, contrary to results found for radio-loud active galactic nuclei (AGNs). Studies of optical emission lines in quasars have revealed a striking set of correlations between various emission-line properties, known as the Boroson & Green eigenvector 1. Until recently it was generally accepted that eigenvector 1 does not depend on orientation, as it strongly correlates with [O III] λ5007 emission, thought to be an isotropic property. However, recent studies of radio-loud AGNs have questioned the isotropy of [O III] emission and concluded that [O II] λ3727 emission is isotropic. In this paper we investigate the relation between eigenvector 1 and [O II] emission in radio-quiet BQS quasars and readdress the issue of orientation as the driver of eigenvector 1. We account for the small blue bump present at [O II] wavelengths and subtract Fe II emission that contaminates [O III] emission. We find significant correlations between eigenvector 1 and orientation-independent [O II] emission, which implies that orientation does not drive eigenvector 1. The luminosities and equivalent widths of [O III] and [O II] correlate with one another, and the range in luminosities and equivalent widths is similar. This suggests that our radio-quiet BQS quasar sample is largely free of orientation-dependent obscuration and/or ionization effects. We conclude that neither the [O III] emission nor the [O II]/[O III] ratio are dependent on orientation in radio-quiet quasars, contrary to recent results found for radio-loud quasars.
Investigation of the Relation between the Spectral Energy Distributions and the Emission Lines in Low‐Redshift Quasars
(IOP Publishing, 1999) Wilkes, Belinda; Kuraszkiewicz, Joanna; Green, Paul J.; Mathur, Smita; McDowell, Jonathan
We investigate the relations between the observed emission-line strengths, widths, and continuum properties of a sample of 41 low-redshift (z<1) quasars for which contemporaneous IR/soft X-ray spectral energy distributions are available. This includes investigating correlations between optical and UV lines with both the luminosity and the shape of the quasars' continuum, as well as correlations between the various lines. The sample is heterogeneous, primarily selected on the existence of good-quality Einstein X-ray data, and includes 18 radio-loud and 23 radio-quiet quasars. We find anticorrelations between the equivalent width and various UV luminosities (the Baldwin effect) for the Lyα and Hβ lines and a marginal anticorrelation for C III]. Exclusion of narrow-line, low-luminosity active galactic nuclei reveals a significant Baldwin effect for the C IV and C III] lines. A significant anticorrelation of EW(C IV) with αox is also present. We find no correlations between any lines and the X-ray luminosity or X-ray slope. The Fe II optical multiplet shows no simple relationship with luminosity or continuum slope; however, there is a tendency for objects with flat X-ray spectra and/or strong X-ray luminosities to have weak Fe II. Our data do not favor a model in which changes in continuum shape (due to, e.g., a decreasing ionization parameter) cause the Baldwin effect. The data can instead be explained by an accretion disk (AD) model in which limb darkening and the projected surface area of an optically thick, geometrically thin disk combine to cause a viewing-angle-dependent UV luminosity and a more isotropic X-ray luminosity. The scatter in our correlations is larger than that expected from this AD model, suggesting the presence of dust, which reddens both the continuum and the broad emission lines. The C IV and C III] lines show flatter slopes and larger scatter in the line-continuum relations than predicted by the AD+dusty torus model. This may be due to a significant contribution from collisional excitation that is not directly related to the ionizing continuum.
Revealing the Heavily Obscured Active Galactic Nucleus Population of High-Redshift 3crr Sources With Chandra X-Ray Observations
(IOP Publishing, 2013) Wilkes, Belinda; Kuraszkiewicz, Joanna; Haas, Martin; Barthel, Peter; Leipski, Christian; Willner, Steven; Worrall, Diana; Birkinshaw, Mark; Antonucci, Robert; Ashby, Matthew; Chini, Rolf; Fazio, Giovanni; Lawrence, Charles; Ogle, Patrick; Schulz, Bernhard
Chandra observations of a complete, flux-limited sample of 38 high-redshift (1 0) indicating obscuration (NH ∼ 1022–1024 cm−2). These properties and the correlation between obscuration and radio core fraction are consistent with orientation-dependent obscuration as in unification models. About half the NLRGs have soft X-ray hardness ratios and/or a high [O iii] emission line to X-ray luminosity ratio suggesting obscuration by Compton thick (CT) material so that scattered nuclear or extended X-ray emission dominates (as in NGC 1068). The ratios of unobscured to Compton-thin (1022 cm−2 < NH(int) < 1.5 × 1024 cm−2) to CT (NH(int) > 1.5 × 1024 cm−2) is 2.5:1.4:1 in this high-luminosity, radio-selected sample. The obscured fraction is 0.5, higher than is typically reported for active galactic nuclei at comparable luminosities from multi-wavelength surveys (0.1–0.3). Assuming random nuclear orientation, the unobscured half-opening angle of the disk/wind/torus structure is ∼60◦ and the obscuring material covers 30◦, ∼12◦ of which is CT. The multi-wavelength properties reveal that many NLRGs have intrinsic absorption 10–1000× higher than indicated by their X-ray hardness ratios, and their true LX values are ∼10–100× larger than the hardness-ratio absorption corrections would indicate.
What Do the Ultraviolet Spectra of Narrow‐Line Seyfert 1 Galaxies Tell Us about Their Broad‐Line Regions?
(IOP Publishing, 2000) Kuraszkiewicz, Joanna; Wilkes, Belinda; Czerny, Bo?ena; Mathur, Smita
We study the UV spectra of narrow-line Seyfert 1 (NLSy1) galaxies and compare them with "normal" active galactic nuclei. Similar to their optical lines, the NLSy1s show narrower UV lines. They are also characterized by weaker C IV λ1549 and C III] λ1909 and stronger Al III λ1857 emission. These UV-line properties add to the optical and X-ray properties known to be part of the Boroson & Green eigenvector 1. We show that the steep soft X-rays, which characterize the NLSy1s SEDs, change the equilibrium of the two-phase cloud-intercloud medium, resulting in somewhat higher broad-line region cloud densities, lower ionization parameter, and larger broad-line region radii. These modified conditions can explain the unusual emission-line properties we find in NLSy1. Using a specific model of an accretion disk with corona presented by Witt, Czerny, & Życki, we also show that the steep soft and hard X-ray continua can be explained if the L/LEdd ratios are larger than in "normal" Sy1s/QSOs, strengthening earlier suggestions that the L/LEdd is the physical parameter driving this eigenvector.
Star formation in z > 1 3CR host galaxies as seen by Herschel
(EDP Sciences, 2015) Podigachoski, P.; Barthel, P. D.; Haas, Mary Elizabeth; Leipski, C.; Wilkes, Belinda; Kuraszkiewicz, Joanna; Westhues, C.; Willner, Steven; Ashby, Matthew; Chini, R.; Clements, D. L.; Fazio, Giovanni; Labiano, A.; Lawrence, C.; Meisenheimer, K.; Peletier, R. F.; Siebenmorgen, R.; Verdoes Kleijn, G.
We present Herschel (PACS and SPIRE) far-infrared (FIR) photometry of a complete sample of z> 1 3CR sources, from the Herschel guaranteed time project The Herschel Legacy of distant radio-loud AGN. Combining these with existing Spitzer photometric data, we perform an infrared (IR) spectral energy distribution (SED) analysis of these landmark objects in extragalactic research to study the star formation in the hosts of some of the brightest active galactic nuclei (AGN) known at any epoch. Accounting for the contribution from an AGN-powered warm dust component to the IR SED, about 40% of our objects undergo episodes of prodigious, ULIRG-strength star formation, with rates of hundreds of solar masses per year, coeval with the growth of the central supermassive black hole. Median SEDs imply that the quasar and radio galaxy hosts have similar FIR properties, in agreement with the orientation-based unification for radio-loud AGN. The star-forming properties of the AGN hosts are similar to those of the general population of equally massive non-AGN galaxies at comparable redshifts, thus there is no strong evidence of universal quenching of star formation (negative feedback) within this sample. Massive galaxies at high redshift may be forming stars prodigiously, regardless of whether their supermassive black holes are accreting or not.
The Far‐Infrared Spectral Energy Distributions of X‐Ray–selected Active Galaxies
(IOP Publishing, 2003) Kuraszkiewicz, Joanna; Wilkes, Belinda; Eric, undefined; Hooper, J.; McLeod, Kim K.; Wood, Kenneth; Bjorkman, Jon; Delain, Kisha M.; Hughes, David H.; Elvis, Martin; Impey, Chris D.; Lonsdale, Carol J.; Malkan, Matt A.; McDowell, Jonathan; Whitney, Barbara
Hard X-ray selection is, arguably, the optimal method for defining a representative sample of active galactic nuclei (AGNs). Hard X-rays are unbiased by the effects of obscuration and reprocessing along the line of sight intrinsic/external to the AGN, which result in unknown fractions of the population being missed from traditional optical/soft X-ray samples. We present the far-infrared (far-IR) observations of 21 hard X-ray-selected AGNs from the HEAO 1 A2 sample observed with Infrared Space Observatory (ISO). We characterize the far-IR continua of these X-ray-selected AGNs and compare them with those of various radio and optically selected AGN samples and with models for an AGN-heated, dusty disk. The X-ray-selected AGNs show broad, warm IR continua covering a wide temperature range (~20-1000 K in a thermal emission scenario). Where a far-IR turnover is clearly observed, the slopes are less than 2.5 in all but three cases so that nonthermal emission remains a possibility, although the presence of cooler dust resulting in a turnover at wavelengths longward of the ISO range is considered more likely. The sample also shows a wider range of optical/UV shapes than the optical/radio-selected samples, extending to redder near-IR colors. The bluer objects are type 1 Seyfert galaxies, while the redder AGNs are mostly intermediate or type 2 Seyfert galaxies. This is consistent with a modified unification model in which obscuration increases as we move from a face-on toward a more edge-on line of sight. However, this relation does not extend to the mid-infrared as the 25/60 μm ratios are similar in Seyfert galaxies with differing type and optical/UV reddening. The resulting limits on the column density of obscuring material through which we are viewing the redder AGNs (NH ~ 1022 cm-2) are inconsistent with standard optically thick torus models (NH ~ 1024 cm-2) and simple unification models. Instead our results support more complex models in which the amount of obscuring material increases with viewing angle and may be clumpy. Such a scenario, already suggested by differing optical/near-IR spectroscopic and X-ray AGN classifications, allows for different amounts of obscuration of the continuum emission in different wave bands and of the broad emission line region, which, in turn, results in a mixture of behaviors for AGNs with similar optical emission-line classifications. The resulting decrease in the optical depth of the obscuring material also allows the AGN to heat more dust at larger radial distances. We show that an AGN-heated, flared, dusty disk with mass of ~109 M☉ and size of approximately a few hundred parsecs is able to generate optical-far-IR spectral energy distributions (SEDs) that reproduce the wide range of SEDs present in our sample with no need for an additional starburst component to generate the long-wavelength, cooler part of the IR continuum.
The Chandra Survey of Extragalactic Sources in the 3cr Catalog: X-Ray Emission From Nuclei, Jets, and Hotspots in the Chandra Archival Observations
(IOP Publishing, 2015) Massaro, F.; Harris, D. E.; Liuzzo, E.; Orienti, M.; Paladino, R.; Paggi, A.; Tremblay, G. R.; Wilkes, Belinda; Kuraszkiewicz, Joanna; Baum, S. A.; O’Dea, C. P.
As part of our program to build a complete radio and X-ray database of all Third Cambridge catalog extragalactic radio sources, we present an analysis of 93 sources for which Chandra archival data are available. Most of these sources have already been published. Here we provide a uniform re-analysis and present nuclear X-ray fluxes and X-ray emission associated with radio jet knots and hotspots using both publicly available radio images and new radio images that have been constructed from data available in the Very Large Array archive. For about 1/3 of the sources in the selected sample, a comparison between the Chandra and radio observations was not reported in the literature: we find X-ray detections of 2 new radio jet knots and 17 hotspots. We also report the X-ray detection of extended emission from the intergalactic medium for 15 galaxy clusters.