Aavso paper Session I sunday Sunday, May 22, 2011, 9: 30 am – 12: 00 pm

327

Blazars, Quasars, and Other AGN

Poster Session

Essex Ballroom

327.01

8:00 AM - 7:00 PM

The Morehead State University 21-Meter Space Tracking Antenna is a particularly unique scientific instrument for pursuing undergraduate research in astrophysics. Current research projects in the radio continuum include pointed observations of Galactic supernova remnants and blazars. In the latter case, undergraduate students and faculty have routinely conducted observations of such well-known blazars as BL Lac, CTA 102 and 3C 454.3: in addition, observations of other blazars detected in outburst at other wavelengths (such as the gamma-ray) have also been observed. We present the results of these observations and an initial analysis of the light curves generated by our observations.

327.02

Similarity of Optical-IR and Gamma-Ray Variability Properties of Fermi Blazars

Ritaban Chatterjee¹, C. Bailyn¹, E. Bonning¹, M. Buxton¹, P. Coppi¹, J. Isler¹, C. M. Urry^1
1Yale Univ..

8:00 AM - 7:00 PM

We present the time variability properties of a sample of six blazars, AO 0235+164, 3C 273, 3C 279, PKS 1510-089, PKS 2155-304, and 3C 454.3, at optical-near IR frequencies observed as a part of the Yale/SMARTS program during 2008-2010. We find the optical/IR time variability properties of these blazars to be remarkably similar to those at the gamma-ray energies as observed through Fermi. The power spectral density (PSD) of the R-band variability of all six blazars are fit well by simple power-law functions with negative slope and no significant break. The negative slope implies there is higher amplitude variability on longer than on shorter timescales. Average slope and amplitude of these PSDs are similar to those of the gamma-ray variability of a larger sample of blazars as found by the Fermi team. This is consistent with the general picture of the leptonic model where the optical-IR and gamma-ray emission is generated by the same population of electrons through synchrotron and inverse-Compton processes, respectively. The prominent flares present in the optical-IR as well as the gamma-ray light curves of these blazars are predominantly symmetric, i.e., have similar rise and decay timescales. This indicates that the long-term variability is dominated by the crossing time of radiation or a disturbance through the emission region and not by the energy-loss timescales of the emitting electrons due to radiation. The total energy output, and the gamma-ray vs. optical flux relation of six individual flares of the blazar 3C 454.3 during 2009 August to December vary significantly from one event to the other. This indicates that the location and/or mechanism of their generation are different. This work was supported by Fermi GI grant NNX09AR92G and NSF grant AST-0707627.

327.03

Intranight Optical Variability of Core Dominated Quasars and TeV Blazars

Paul J. Wiita¹, A. Goyal², G. Krishna², G. C. Anupama³, D. K. Sahu³, S. Joshi⁴, C. Karthick⁴, R. Sagar^4
1The College of New Jersey, ²National Centre for Radio Astrophysics, India, ³Indian Institute of Astrophysics, India, ⁴ARIES, India.

8:00 AM - 7:00 PM

We have investigated the intranight optical variability (INOV) of powerful flat spectrum core dominated radio quasars (CDQs) and TeV blazars to test unification models of radio-loud AGN. A sample of 15 CDQs, including both low-polarization and high-polarization objects, were observed at three sites in India on 49 nights; with data from the literature this sample was extended to 24 CDQs and 110 nights. The INOV duty cycle was about 18% for the low polarization sub-sample but about 66% for the high polarization sub-sample. Given that all these CDQs had synchrotron self-absorbed cores all should be relativistically beamed, so this difference indicates that optical polarization is more strongly linked with rapid variability than is relativistic beaming. For the first systematic attempt to characterize the INOV of TeV detected blazars we monitored 9 of them over 26 nights and have included additional data (some from our earlier studies) on 13 more for a total of 22 TeV blazars observed on 116 nights. The overall INOV duty cycle for this group is about 59%, with the LBLs distinctly more variable than the HBLs. Given that the Doppler boosting factors for TeV blazars are expected to be very high, it is somewhat surprising that no variations faster than one hour were seen for any members of the TeV sample.

327.04

A Model for Microvariability in Blazars

Gopal Bhatta¹, J. Webb¹, S. Dhalla¹, H. Hallingsworth^1
1Florida International University.

8:00 AM - 7:00 PM

We present a model based on the results of nearly 10 years of the study of microvariability in a sample of Blazars. The model is based on the facts that: 1) The variations do not show the characteristics of random noise, 2) The variations are not periodic, 3) The variations are best described as stochastically generated pulses of varying amplitude and durations. We show microvariability curves dissected with this interpretation in mind, and propose a theoretical underpinning for this model based on shocks encountering turbulent cells and cooling via synchrotron radiation. We show microvariations (and the lack of them) can be understood in terms of this model. We also describe an observational test to investigate the validity of this model.

327.05

Doubling the Sample of Jet Speed Measurements for the TeV Blazars

B. Glenn Piner¹, V. C. Tiet¹, P. G. Edwards^2
1Whittier College, ²CSIRO, Australia.

8:00 AM - 7:00 PM

We report on our observations of the parsec-scale radio jet structures of five blazars that have been detected by ground-based TeV gamma-ray telescopes. These five blazars all belong to the class of High-frequency peaked BL Lac objects (HBLs), which are the most common blazar type detected at the TeV energy range. Because of their relative faintness in the radio, these HBLs are not well represented in other radio blazar surveys. Our observations consist of five epochs of Very Long Baseline Array (VLBA) imaging from 2006 to 2009, of each of the five blazars 1ES 1101-232, Markarian 180, 1ES 1218+304, PG 1553+113, and H 2356-309, at frequencies from 5 to 22 GHz. Fundamental jet properties, including the apparent jet speeds, that can be measured from these multi-epoch series of VLBA images are presented and compared with other gamma-ray blazars. This study approximately doubles the number of TeV blazars with multi-epoch parsec-scale structural measurements. This work was supported by the National Science Foundation under Grant 0707523.

327.06

Analysis of Parsec-Scale Jet Behavior of a Sample of Blazars during High Gamma-Ray States

Svetlana G. Jorstad¹, A. P. Marscher¹, I. Agudo¹, B. Harrison^1
1Boston Univ..

8:00 AM - 7:00 PM

We present total and polarized intensity images at ultra-high resolution (0.1 milliarcseconds) of a sample of 33 gamma-ray blazars obtained monthly with the Very Long Baseline Array (VLBA) at 43~GHz, starting in Summer 2008 when the Fermi Gamma-Ray Space Telescope began to operate. The VLBA observations determine the flux and polarization of the millimeter-wave core and other components of the jet, as well as the kinematics and evolution of bright superluminal knots. We compare the gamma-ray light curves of the blazars, constructed with data provided by the Fermi Large Area Telescope, with flux and polarization variations in the VLBI core and bright superluminal knots. For all blazars in the sample that exhibit a high gamma-ray state on time scales from several weeks to several months, an increase of the total flux in the mm-wave core is contemporaneous with the gamma-ray activity (more than a third of the sample). In addition, a maximum of the degree of polarization in the core or bright superluminal knot nearest to the core occurs at the same time as the gamma-ray peak to within the accuracy of the sampling of the radio data. We discuss the locations in the jet where high gamma-ray fluxes occur, as well as the physical processes leading to luminous gamma-ray emission in blazars.

327.07
Simulations Of Millimeter-wave To Gamma-ray Flares Of Blazars In A Turbulent Jet

8:00 AM - 7:00 PM

The author is developing a model in which much of the optical and high-energy radiation in a blazar is emitted near the 43 GHz core of the jet as seen in VLBA images, parsecs from the central engine. The main physical features are a turbulent ambient jet plasma that passes through either standing or moving shock waves in the jet. The model allows for short time-scales of optical and gamma-ray variability by restricting the highest-energy electrons radiating at these frequencies to a small fraction of the turbulent cells, perhaps those with a particular orientation of the magnetic field relative to the shock front. Because of this, the volume filling factor at high frequencies is relatively low, while that of the electrons radiating below about 10 THz is near unity. Such a model is consistent with the following observational trends: (1) red-noise power spectra of flux variations in blazars, (2) shorter time-scales of variability of flux and polarization at higher frequencies, (3) mean polarization levels as well as fractional deviations from the mean that are higher at optical than at lower frequencies, (4) apparent rotations in polarization position angle, and (5) breaks in the synchrotron spectrum by more than the radiative loss value of 0.5. The dependence of items 2-4 on frequency is directly related to the change in spectral index beyond the break, according to the model.

327.08

8:00 AM - 7:00 PM

We have used mid-infrared selection to find several tens of dust obscured quasars at z>2. We find that many of these objects have host galaxies with high stellar masses, commensurate with their high black hole masses (assuming Eddington-limited accretion rates). In common with some other studies of obscured AGN and quasars we do not find evidence for black hole masses in excess of the local black hole mass - bulge mass relation. The molecular gas content of these objects is small compared to their stellar masses. These observations are all consistent with the quasar hosts being relatively mature systems when observed.

327.09

Optical+Near-IR Bayesian Classification of Quasars

Sajjan S. Mehta¹, G. T. Richards¹, A. D. Myers^2
1Drexel University, ²University of Illinois at Urbana-Champaign.

8:00 AM - 7:00 PM

327.10

8:00 AM - 7:00 PM

We explore the spectral energy distribution (SED) for up to 100,000 SDSS-selected quasars using mid-IR data from Spitzer, near-IR data from 2MASS and UKIDSS, optical data from SDSS, and UV data from GALEX. We consider the problem of determining bolometric corrections for individual quasars as opposed to the ensemble average. Significant differences can arise due to the fact that even the best observed SEDs have a gap of nearly 2 decades in frequency between the UV and X-ray. We particularly consider the dependence of the bolometric correction on the UV luminosity and the properties of the CIV emission line. The latter can be used to distinguish between hard-spectrum radio-quiet quasars and soft-spectrum radio-quiet quasars, which can have very different bolometric corrections for the same UV luminosity and thus different Eddington ratios.

327.11

Red Radio-intermediate Quasars From The Wise Survey

Carol J. Lonsdale¹, M. Kim¹, J. Condon¹, M. Lacy¹, A. Kimball¹, T. Jarrett², C. Tsai², A. Blain³, WISE
¹NRAO, ²IPAC, ³University of Leicester, United Kingdom.

8:00 AM - 7:00 PM

The first catalog release from NASA's Wide-field Infrared Survey Explorer (WISE) mission, covering 57% of the sky, is scheduled for April. The WISE catalog has been cross-matched with the FIRST and NVSS radio surveys, resulting in ~30,000 matches to WISE mid-infrared sources. We will present overall statistics for the observed range of color and radio/mid-IR flux density ratio. A subset of ~200 radio-intermediate sources with very red optical-to-mid-IR SEDs and evidence for some extent to the 6cm radio emission has been selected for detailed study.

327.12

Modeling the Hβ Emission Lines in Luminosity-Averaged Quasar Spectra

Meadows Zachary¹, S. Zamfir¹, P. Marziani², J. W. Sulentic^3
1University of Wisconsin - Stevens Point, ²INAF-Osservatorio Astronomico di Padova, Italy, ³Instituto de Astrofísica de Andalucia, Spain.

8:00 AM - 7:00 PM

327.13

8:00 AM - 7:00 PM

At high redshift two parameters span the range of emission line properties in quasar broad emission line regions: the CIV equivalent width and the blueshift of the CIV line relative to the quasar rest frame. We explore the connection between these emission line features and the UV through X-ray spectral energy distribution (SED) for radio-quiet quasars. We find that radio-quiet quasars with both strong CIV emission and small CIV blueshifts can be classified as ``hard-spectrum'' sources that are (relatively) strong the in X-ray as compared to the UV. The low-energy X-ray upturn (``soft excess'') in some quasars may be consistent with the high-energy extension of the ``big blue bump'' in hard-spectrum sources. On the other hand, RQ quasars with both weak CIV emission and large CIV blueshifts are instead ``soft-spectrum'' sources. The nature of sources with weak CIV and small blueshifts is less clear and needs further study. We argue that bolometric corrections for quasars may have systematic errors if a single mean SED is assumed for all objects, leading to additional systematic errors in accretion rates as determined by L_bol/M_vir. Bolometric corrections can instead be considered as a function of the ionizing spectrum, which can be inferred from the properties of the broad emission lines, particularly CIV.

327.14

8:00 AM - 7:00 PM

Despite the debate as to whether a dichotomy between radio-loud and radio-quiet quasars actually exists, the fact remains that some quasars are radio-loud while others are not. Using median stacking analysis of SDSS quasars undetected by FIRST, we search for possible radio-silence amongst various sub-samples with different broad emission line properties. Specifically, we find that the combination of two parameters of the CIV emission line (the equivalent width and the "blueshift") can be used to determine the ionizing spectrum of individual quasars. Quasars with strong CIV are seen to have hard (ionizing) SEDs, while quasars with large blueshifts are seen to have softer SEDs. The shape of the SED depends on fundamental parameters such as mass, accretion rate, and spin; radio-loudness may be dependent on these parameters. As such, our CIV emission line parameter space affords a unique way to probe the radio properties of quasars. We predict that those radio-quiet quasars with the least ionizing spectra will have very different median stacked peak flux values than radio-quiet quasars with hard ionizing spectra. We further break our sample into smaller subsets (e.g., based on optical luminosity) to explore the radio-dependence on these parameters. Stacking subsets of quasars undetected by FIRST offers fresh new insight to a frustratingly stagnant problem.

327.15

The Kiloparsec-scale Jet Of The Quasar 3C345

David H. Roberts¹, J. F. C. Wardle¹, V. V. Marchenko^1
1Brandeis Univ..

8:00 AM - 7:00 PM

Deep Very Large Array imaging of the quasar 3C345 has been used to study the structure, linear polarization, and magnetic field of its radio jet at 4.86 and 8.44 GHz on scales ranging from 2 to 30 kpc. There is a 7-8 Jy unresolved core with spectral index -0.24. The jet (typical intensity 15 mJy/beam) consists of a 2.5 arcsec straight section containing two knots, and two additional non-co-linear knots at the end. The spectral index of the jet varies between -1.1 and -0.5. The main body of the jet diverges slightly, with an apparent opening half-angle of about 8 degrees; de-projected, the intrinsic opening angle is probably about 1-2 degrees. Surprisingly, the inferred magnetic field direction in the interior of the main body of the jet is neither longitudinal nor transverse, but makes an angle of about 55 degrees with the jet axis, in an apparent helix. There is no significant Faraday rotation in the source, so that is not the cause of the field twist. The fractional polarization in the jet averages 25%, while that of the core is only 3%. Despite the indication of jet precession in the total intensity structure, the polarization images suggest instead a jet re-directed at least twice by collisions with the external medium. Simple models of magnetized jets are investigated in order to study various possible origins of the magnetic field morphology. In a cylindrically symmetric transparent jet a helical magnetic field would appear either transverse or longitudinal due to partial cancellations of Stokes parameters. Synchrotron opacity can break the symmetry, but it leads to fractional polarization far less than that observed. We investigate whether differential Doppler boosting in a diverging jet can break the symmetry, allowing a truly helical jet to appear helical.

327.16

Nozzle Analysis and Line-Driven Disk Winds in QSOs

Nicolas Antonio Pereyra^1
1University of Texas - Pan American.

8:00 AM - 7:00 PM

An analytic method for determining the existence or non-existence of steady line-driven solutions is implemented for disk winds with QSO parameters. This method is independent of numerical time-dependent computationally-intensive simulations , and it is found that steady disk wind solutions for QSOs do exist. This is consistent with the steady wind outflow velocity structure observed in QSOs.

327.17

Probing Emission And Absorption Processes In AGNs With MHD Accretion-Disk Winds

Keigo Fukumura¹, D. Kazanas², E. Behar³, I. Contopoulos^4
1CRESST/UMBC/GSFC, ²NASA/GSFC, ³Department of Physics, Technion, Israel, ⁴Academy of Athens, Greece.

8:00 AM - 7:00 PM

It is well known from the past optical/EUV observations that a small population of AGNs exhibits the so called broad double-peaked Balmer line profiles (FWHM~10,000 km/sec); i.e. ~20% of the radio-galaxies (RGs) and radio-loud (RL) AGNs at z<0.4 while only 3-4% of SDSS AGNs at z<0.33 (e.g. Arp 102B and 3C 390.3). Its theoretical interpretation has been based on a Keplerian accretion disk where line photons are Doppler-shifted due to rotation to form the broadened red/blue tails although the predicted line strength is critically smaller than the observed intensity. As an alternative explanation to resolve this issue, we propose that magnetically-driven disk-winds can self-consistently reproduce both i) broad double-peaked line shape and ii) its normalization for many observed objects including those with single-peaked profiles. Our preliminary results suggest that the apparent spectral distinction in various Balmer lines can be accounted for by the wind structure as well as viewing angle. This line emission model is a continuation of our earlier work on absorption lines for Seyfert AGNs and BAL quasars, and we here demonstrate how both spectral signatures can be explained within this single disk-wind scenario.

327.18

Origins of X-Shaped Radio Galaxies

Robert Sobczak¹, J. Starr¹, P. J. Wiita^1
1The College of New Jersey.

8:00 AM - 7:00 PM

Four viable explanations for the development of the characteristic morphology of X-shaped radio galaxies (XRGs) have been presented in the literature. These established models involve: backflowing material from relativistic jets deflected off the host galaxy ISM; over-pressured cocoons leading to outflow along a galaxy’s minor axis; rapid jet reorientation (spin-flip), presumably involving the merger of two supermassive black holes; or the interaction of jets with stellar and gaseous shells that arise from the merger of two galaxies. None of these models appears to be able to account for the morphology of all observed XRGs, but images of these sources can be used to decide which of these models provide good fits to individual XRGs. We have examined a sample of 100 XRG candidates and tabulated several different measured parameters based on their morphology and power. The key morphology parameters are the lengths and widths of the primary and secondary lobes. We then classified the XRGs in this sample as to the most likely model or models able to explain their characteristics. Our main conclusion is that the spin-flip and jet interaction with shells models provide better fits to the majority of sources than do the backflow or over-pressured cocoon models.

327.19

8:00 AM - 7:00 PM

While there are many explanations for the formation of the apparently small subset of radio galaxies that display an X-shaped morphology (XRGs), an important but often overlooked aspect of observing XRGs is the substantial problem encountered due to projection effects. A physically well-defined XRG will not appear X-shaped if viewed from certain angles. Thus, it is quite probable that many galaxies that have been observed and classified as having other shapes, in particular, some of the double-double radio sources, may in fact be XRGs. To more accurately determine the likelihood of an XRG appearing non-X-shaped, we developed a computer algorithm to model fiducial XRGs and develop probabilities of an observation leading to classification errors due to projection effects. The program randomly generates viewing angles for different XRG models, and these are then categorized as to whether or not they appear X-shaped to the observer. Knowing they are in fact X-shaped, however, provides a statistical probability for observing an XRG and yet misclassifying its shape. By repeating this process for many viewing angles and for a variety of XRG models, we are able to analyze the likelihood of actual XRGs appearing non-X-shaped.

327.20

Determining the Contribution to Feedback from Low Accretion Rate AGN

Lisa M. Winter^1
1CASA/University of Colorado-Boulder.

8:00 AM - 7:00 PM

While feedback from the central supermassive black hole likely affects the host galaxy evolution in the distant universe, we can not directly observe these processes at work. We can, however, easily observe the host galaxy and AGN properties of nearby sources. Previous surveys of outflows in local AGN relied on biased samples of the UV/soft X-ray brightest sources, making their results also biased. To understand the true outflow properties in a local sample of AGN, we present our results from optical and X-ray spectroscopic follow-ups of a sample of Seyfert 1s detected in the very hard X-rays (14-195 keV) with the Swift Burst Alert Telescope. Due to the high energy selection, this survey is largely unbiased to the gas and dust which obscures softer bands. We find that outflows are detected in a majority of the sample and may be present in all local Seyfert 1s. This implies a covering fraction of the outflows much larger than previous results, which means that more kinetic energy is available in the outflows of low luminosity sources than previously thought.

327.21

A Decade of Variability in Centaurus A: Results from Chandra/ACIS Observations

Matthew Barger¹, T. Calnan^1
1Elon University.

8:00 AM - 7:00 PM

We present results from a decade of Chandra observations of the nucleus in the nearest radio-loud AGN, Centaurus A. We use Chandra’s exquisite spatial resolution to separate the unresolved nucleus from emission associated with the jet, gas, and X-ray binaries, thereby allowing us to probe variability on scales less than the Bondi radius. We search for variability in the absorbing column and power-law emission, and interpret our results in the context of AGN unification models.

327.22

8:00 AM - 7:00 PM

Broad iron K emission lines are not always seen in the X-ray spectra of type 1 AGN, in spite of their high accretion rates that imply an optically-thick disk extending down to at or near the innermost stable circular orbit (ISCO), and the unobscured line-of-sight to their X-ray sources. The reason for the notable lack of relativistic disk signatures in many type-1 AGN is unknown. We have made high S/N (~600,000 counts) Suzaku observations of NGC 5548 to set tight limits on any broad Fe K line at EW<40 eV in the summed spectrum,or <100 eV in most of the individual spectra. We compare the properties of NGC 5548 with the famously strong broad Fe K emitter MCG--6-30-15. The two AGNs are similar in several parameters (X-ray luminosity, optical-to-X-ray slope, host type), but differ strongly in black hole mass (a factor ~15), radio-loudness (a factor ~10, though both are formally radio-quiet) and Eddington ratio (a factor ~50). The low Eddington ratio (~2%) of NGC 5548 is close to the transition value to a jet-dominated low/hard state in X-ray binaries, where the inner accretion disk has withdrawn, which would narrow any relfected line emission. The higher radio-loudness of NGC 5548 may then be related to a nascent jet. However, this scenario is complicated by the presence of strong optical and UV emission lines indicating the presence of an optically-thick disk at small radii. We also examine where the X-ray continuum in NGC 5548 could originate in light-bending models in order to explain the lack of a broad Fe K line.

327.23

Narrow Line Seyfert 1 Galaxies from the Final Data Release of SDSSII

Aycha Tammour¹, P. B. Eskridge^1
1Minnesota State University.

8:00 AM - 7:00 PM

We present a study of a sample of Narrow Line Seyfert 1 (NLS1) candidates extracted from the seventh data release of the Sloan Digital Sky Survey SDSSII. The sample is restricted to objects from the QSO database that are detected by ROSAT and have z < 0.39, FWHM(Hα) < 4000 km.s⁻¹ and FWHM(Hβ) < 4000 km.s⁻¹ as determined by the SDSS pipeline. We fit Hβ with a Gaussian and a Lorentzian in order to examine the various properties of the spectra with the width of the Lorentzian Hβ. We also look at the properties of the sample above the classic NLS1 cut-off of FWHM(Hβ) < 2000 km.s⁻¹ .

327.24

8:00 AM - 7:00 PM

The AGN NGC 2110 presents a peculiar case among the Seyfert 2 galaxies, as it displays also features of radio-loud objects and is classified as FR-I radio galaxy. Here we analyse simultaneous INTEGRAL and Swift data taken in 2008 and 2009. We reconstruct the spectral energy distribution in order to provide further insight. The combined X-ray spectrum is well represented by an absorbed cut-off power law model plus soft excess. Combining all available data, the spectrum appears flat (photon index 1.25 ± 0.04) with the high-energy cut-off being at E_C = 82 ± 9 keV. The absorption is moderate (NH = 4E22 1/cm**2), the iron K-alpha line is weak (EW = 114 eV), and no reflection component is detected in the INTEGRAL spectrum. The data indicate that the X-ray spectrum is moderately variable both in flux and spectral shape. The 2008 spectrum is slightly steeper (photon index 1.5, E_C = 90 keV) with the source being brighter, and flatter in 2009 (photon index 1.4, E_C = 120 keV) in the lower flux state. The spectral energy distribution gives a bolometric luminosity of L = 2E44 erg/sec. NGC 2110 appears to be a borderline object between radio loud narrow line Seyfert 1 and radio quiet Seyfert 2. Its spectral energy distribution might indeed be dominated by non-thermal emission arising from the jet.

327.25

8:00 AM - 7:00 PM

We acquired optical spectra of ten newly discovered Swift BAT AGN for the first time and determined redshifts, optical properties, and classifications for each galaxy. The sources were detected in the 55-month survey in the hard X-ray regime of 14-195 keV. The BAT sample provides an unbiased look at AGN because at these wavelengths dust and gas obscuration does not prevent their detection. The optical follow-ups were done on the 3.5-meter Apache Point Observatory in New Mexico using the lower dispersion DIS gratings, which provides a large wavelength coverage. As the Swift survey continues, it probes to fainter and more distant objects. For the new AGN in the catalog, we present an analysis of the optical and X-ray spectroscopy. Optical spectroscopy of these new targets, discovered as AGN for the first time through their hard X-ray flux, are more distant than the average Swift source with a redshift range of z= 0.02 to 0.15 and an average redshift in the sample of z= 0.07. Half (5 sources) of our sample exhibit broad lines in their optical spectra, which is characteristic of Seyfert 1 galaxies, while the other half have narrow emission lines which are characteristic of Seyfert 2 galaxies. Additionally, we analyzed the X-ray spectra and created SEDs for these sources.

327.26

Multi-wavelength Diagnostics of the AGN/Star-formation Connection

Stephanie M. LaMassa^1
1Johns Hopkins Univ..

8:00 AM - 7:00 PM

We are studying the relationship between black hole growth and star formation activity using a sample of ~300 star-forming and composite AGN/star-forming galaxies and a sample of ~50 AGN dominated sources. Using Spitzer IRS and Sloan Digital Sky Survey (SDSS) spectra, we will investigate the optical and mid-infrared parameter space in which these sources live. We will present the relationships among proxies that trace intrinsic AGN luminosity (e.g. [OIII] 5007 Angstrom, [NeV] 14 micron and mid-infrared continuum luminosities), star formation activity (e.g. optically derived star formation rates from SDSS and IR star formation rates from the [NeII] 12.8 micron and [NeIII] 15.6 micron emission lines, polycyclic aromatic hydrocarbon (PAH) luminosities) and the relative importance of AGN and starburst processes (e.g. PAH equivalent widths, the optical ``D'' parameter, the mid-infrared spectral index, ionization field hardness). For the sample of AGN, we will include the soft X-ray (0.5 - 2 keV) perspective, from Chandra and XMM-Newton analysis, on the relative contributions of AGN to star formation activity.