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Full-Text Articles in Physical Sciences and Mathematics
The Puzzling Case Of The Radio-Loud Qso 3c 186: A Gravitational Wave Recoiling Black Hole In A Young Radio Source?, Marco Chiaberge, Eric S. Perlman
The Puzzling Case Of The Radio-Loud Qso 3c 186: A Gravitational Wave Recoiling Black Hole In A Young Radio Source?, Marco Chiaberge, Eric S. Perlman
Aerospace, Physics, and Space Science Faculty Publications
Context. Radio-loud active galactic nuclei with powerful relativistic jets are thought to be associated with rapidly spinning black holes (BHs). BH spin-up may result from a number of processes, including accretion of matter onto the BH itself, and catastrophic events such as BH-BH mergers. Aims. We study the intriguing properties of the powerful (Lbol ∼ 1047 erg s-1) radio-loud quasar 3C 186. This object shows peculiar features both in the images and in the spectra. Methods. We utilize near-IR Hubble Space Telescope (HST) images to study the properties of the host galaxy, and HST UV and Sloan Digital Sky Survey …
A Multi-Band Study Of The Remarkable Jet In Quasar 4c+19.44, Daniel E. Harris, Eric S. Perlman
A Multi-Band Study Of The Remarkable Jet In Quasar 4c+19.44, Daniel E. Harris, Eric S. Perlman
Aerospace, Physics, and Space Science Faculty Publications
We present arcsecond-resolution data in the radio, IR, optical, and X-ray for 4C+19.44 (=PKS 1354+195), the longest and straightest quasar jet with deep X-ray observations. We report results from radio images with half to one arcsecond angular resolution at three frequencies, plus Hubble Space Telescope and Spitzer data. The Chandra data allow us to measure the X-ray spectral index in 10 distinct regions along the 18″ jet and compare with the radio index. The radio and X-ray spectral indices of the jet regions are consistent with a value of throughout the jet, to within uncertainties. The X-ray jet structure to …
An Hst Proper-Motion Study Of The Large Scale Jet Of 3c273, Eileen T. Meyer, William B. Sparks, Markos Georganopoulos, Jay Anderson, Roeland Van Der Marel, John Biretta, Sangmo Tony Sohn, Marco Chiaberge, Eric S. Perlman, Colin Norman
An Hst Proper-Motion Study Of The Large Scale Jet Of 3c273, Eileen T. Meyer, William B. Sparks, Markos Georganopoulos, Jay Anderson, Roeland Van Der Marel, John Biretta, Sangmo Tony Sohn, Marco Chiaberge, Eric S. Perlman, Colin Norman
Aerospace, Physics, and Space Science Faculty Publications
The radio galaxy 3C 273 hosts one of the nearest and best-studied powerful quasar jets. Having been imaged repeatedly by the Hubble Space Telescope (HST) over the past twenty years, it was chosen for an HST program to measure proper motions in the kiloparsec-scale resolved jets of nearby radio-loud active galaxies. The jet in 3C 273 is highly relativistic on sub-parsec scales, with apparent proper motions up to 15c observed by very long baseline interferometry. In contrast, we find that the kiloparsec-scale knots are compatible with being stationary, with a mean speed of -0.2 ±0.5c over the whole jet. Assuming …
Powerful Activity In The Bright Ages. I. A Visible/Ir Survey Of High Redshift 3c Radio Galaxies And Quasars, Bryan Hilbert, Eric S. Perlman
Powerful Activity In The Bright Ages. I. A Visible/Ir Survey Of High Redshift 3c Radio Galaxies And Quasars, Bryan Hilbert, Eric S. Perlman
Aerospace, Physics, and Space Science Faculty Publications
We present new rest-frame UV and visible observations of 22 high-z (1 < z < 2.5) 3C radio galaxies and QSOs obtained with the Hubble Space Telescope's Wide Field Camera 3 instrument. Using a custom data reduction strategy in order to assure the removal of cosmic rays, persistence signal, and other data artifacts, we have produced high-quality science-ready images of the targets and their local environments. We observe targets with regions of UV emission suggestive of active star formation. In addition, several targets exhibit highly distorted host galaxy morphologies in the rest frame visible images. Photometric analyses reveal that brighter QSOs generally tend to be redder than their dimmer counterparts. Using emission line fluxes from the literature, we estimate that emission line contamination is relatively small in the rest frame UV images for the QSOs. Using archival VLA data, we have also created radio map overlays for each of our targets, allowing for analysis of the optical and radio axes alignment.
Chang-Es V: Nuclear Outflow In A Virgo Cluster Spiral After A Tidal Disruption Event, Judith A. Irwin, Richard N. Henriksen, Marita Krause, Daniel Q. Wang, Theresa Wiegert, Eric J. Murphy, George Heald, Eric S. Perlman
Chang-Es V: Nuclear Outflow In A Virgo Cluster Spiral After A Tidal Disruption Event, Judith A. Irwin, Richard N. Henriksen, Marita Krause, Daniel Q. Wang, Theresa Wiegert, Eric J. Murphy, George Heald, Eric S. Perlman
Aerospace, Physics, and Space Science Faculty Publications
We have observed the Virgo Cluster spiral galaxy, NGC 4845, at 1.6 and 6 GHz using the Karl G. Jansky Very Large Array, as part of the Continuum Halos in Nearby Galaxies—an EVLA Survey (CHANG-ES). The source consists of a bright unresolved core with a surrounding weak central disk (1.8 kpc diameter). The core is variable over the 6 month timescale of the CHANG-ES data and has increased by a factor of ≈6 since 1995. The wide bandwidths of CHANG-ES have allowed us to determine the spectral evolution of this core, which peaks between 1.6 and 6 GHz (it is …
Optical Detection Of The Pictor A Jet And Tidal Tail: Evidence Against An Ic/Cmb Jet, Eric S. Gentry, Herman L. Marshall, Martin J. Hardcastle, Eric S. Perlman, Mark Birkinshaw, Diana M. Worrall, Emil Lenc, Aneta Siemiginowska, Claudia Megan Urry
Optical Detection Of The Pictor A Jet And Tidal Tail: Evidence Against An Ic/Cmb Jet, Eric S. Gentry, Herman L. Marshall, Martin J. Hardcastle, Eric S. Perlman, Mark Birkinshaw, Diana M. Worrall, Emil Lenc, Aneta Siemiginowska, Claudia Megan Urry
Aerospace, Physics, and Space Science Faculty Publications
New images of the FR II radio galaxy Pictor A from the Hubble Space Telescope reveal a previously undiscovered tidal tail, as well as a number of jet knots coinciding with a known X-ray and radio jet. The tidal tail is approximately 5″ wide (3 kpc projected), starting 18″ (12 kpc) from the center of Pictor A, and extends more than 90″ (60 kpc). The knots are part of a jet observed to be about 4′ (160 kpc) long, extending to a bright hotspot. These images are the first optical detections of this jet, and by extracting knot flux densities …
Ruling Out Ic/Cmb X-Rays In Pks 0637-752 And The Implications For Tev Emission From Large-Scale Quasar Jets, Eileen T. Meyer, Markos Georganopoulos, William B. Sparks, Leith E.H. Godfrey, James E.J. Lovell, Eric S. Perlman
Ruling Out Ic/Cmb X-Rays In Pks 0637-752 And The Implications For Tev Emission From Large-Scale Quasar Jets, Eileen T. Meyer, Markos Georganopoulos, William B. Sparks, Leith E.H. Godfrey, James E.J. Lovell, Eric S. Perlman
Aerospace, Physics, and Space Science Faculty Publications
The Chandra X-ray observatory has discovered dozens of resolved, kiloparsec-scale jets associated with powerful quasars in which the X-ray fluxes are observed to be much higher than the expected level based on the radio-optical synchrotron spectrum. The most popular explanation for the anomalously high and hard X-ray fluxes is that these jets do not decelerate significantly by the kiloparsec scale, but rather remain highly relativistic (Lorentz factors ). By adopting a small angle to the line of sight, the X-rays can thus be explained by inverse Compton upscattering of cosmic microwave background (CMB) photons (IC/CMB), where the observed emission is …
The Differences In The Torus Geometry Between Hidden And Non-Hidden Broad Line Active Galactic Nuclei, Kohei Ichikawa, Eric S. Perlman
The Differences In The Torus Geometry Between Hidden And Non-Hidden Broad Line Active Galactic Nuclei, Kohei Ichikawa, Eric S. Perlman
Aerospace, Physics, and Space Science Faculty Publications
We present results from the fitting of infrared (IR) spectral energy distributions of 21 active galactic nuclei (AGNs) with clumpy torus models. We compiled high spatial resolution (∼0.3–0.7 arcsec) mid-IR (MIR) N-band spectroscopy, Q-band imaging, and nuclear near- and MIR photometry from the literature. Combining these nuclear near- and MIR observations, far-IR photometry, and clumpy torus models enables us to put constraints on the torus properties and geometry. We divide the sample into three types according to the broad line region (BLR) properties: type-1s, type-2s with scattered or hidden broad line region (HBLR) previously observed, and type-2s without any published …
Spitzer Space Telescope Measurements Of Dust Reverberation Lags In The Seyfert 1 Galaxy Ngc 6418, Billy Vazquez, Dan Batcheldor
Spitzer Space Telescope Measurements Of Dust Reverberation Lags In The Seyfert 1 Galaxy Ngc 6418, Billy Vazquez, Dan Batcheldor
Aerospace, Physics, and Space Science Faculty Publications
We present results from a 15 month campaign of high-cadence (∼3 days) mid-infrared Spitzer and optical (B and V) monitoring of the Seyfert 1 galaxy NGC 6418, with the objective of determining the characteristic size of the dusty torus in this active galactic nucleus (AGN). We find that the 3.6 and 4.5 μm flux variations lag behind those of the optical continuum by 37.2 ^+2.4 _-2.2 days and -47.1 ^+3.1 _-3.1 days, respectively. We report a cross-correlation time lag between the 4.5 and 3.6 μm flux of 13.9 ^+0.5 _-0.1 days. The lags indicate that the dust emitting at 3.6 …
Recoiling Supermassive Black Holes: A Search In The Nearby Universe, Davide Lena, Andrew Edward Robinson, Alessandro Marconi, David J. Axon, Alessandro Capetti, David Merritt, Daniel P. Batcheldor
Recoiling Supermassive Black Holes: A Search In The Nearby Universe, Davide Lena, Andrew Edward Robinson, Alessandro Marconi, David J. Axon, Alessandro Capetti, David Merritt, Daniel P. Batcheldor
Aerospace, Physics, and Space Science Faculty Publications
The coalescence of a binary black hole can be accompanied by a large gravitational recoil due to anisotropic emission of gravitational waves. A recoiling supermassive black hole (SBH) can subsequently undergo long-lived oscillations in the potential well of its host galaxy, suggesting that offset SBHs may be common in the cores of massive ellipticals. We have analyzed Hubble Space Telescope archival images of 14 nearby core ellipticals, finding evidence for small (≲ 10 pc) displacements between the active galactic nucleus (AGN; the location of the SBH) and the center of the galaxy (the mean photocenter) in 10 of them. Excluding …
Polarized Mid-Infrared Synchrotron Emission In The Core Of Cygnus A, Enrique López Rodríguez, Eric S. Perlman
Polarized Mid-Infrared Synchrotron Emission In The Core Of Cygnus A, Enrique López Rodríguez, Eric S. Perlman
Aerospace, Physics, and Space Science Faculty Publications
We present high-angular (∼0". 4) resolution mid-infrared (MIR) polarimetric observations in the 8.7μm and 11.6μm filters of Cygnus A using CanariCam on the 10.4 m Gran Telescopio CANARIAS. A highly polarized nucleus is observed with a degree of polarization of 11% ±3% and 12% ±3% and a position angle of polarization of 27◦ ±8◦ and 35◦ ± 8◦ in a 0.".38 (∼380 pc) aperture for each filter. The observed rising of the polarized flux density with increasing wavelength is consistent with synchrotron radiation from the parsec-scale jet close to the core of Cygnus A. Based on our polarization model, the …
Subaru Spectroscopy And Spectral Modeling Of Cygnus A, Matthew J. Merlo, Eric S. Perlman, Robert Nikutta, Christopher Packham, Moshe Elitzur, Masatoshi Imanishi, Nancy A. Levenson, James T. Radomski, Itziar Aretxaga
Subaru Spectroscopy And Spectral Modeling Of Cygnus A, Matthew J. Merlo, Eric S. Perlman, Robert Nikutta, Christopher Packham, Moshe Elitzur, Masatoshi Imanishi, Nancy A. Levenson, James T. Radomski, Itziar Aretxaga
Aerospace, Physics, and Space Science Faculty Publications
We present high angular resolution (∼0.″5) MIR spectra of the powerful radio galaxy, Cygnus A (Cyg A), obtained with the Subaru telescope. The overall shape of the spectra agree with previous high angular resolution MIR observations, as well as previous Spitzer spectra. Our spectra, both on and off nucleus, show a deep silicate absorption feature. The absorption feature can be modeled with a blackbody obscured by cold dust or a clumpy torus. The deep silicate feature is best fit by a simple model of a screened blackbody, suggesting that foreground absorption plays a significant, if not dominant, role in shaping …
Extended Warm Gas In The Ulirg Mrk273: Galactic Outflows And Tidal Debris, Javier Rodríguez Zaurín, Clive N. Tadhunter, David S.N. Rupke, Sylvain Veilleux, Henrik W.W. Spoon, Marco Chiaberge, Cristina Ramos Almeida, Dan Batcheldor, William B. Sparks
Extended Warm Gas In The Ulirg Mrk273: Galactic Outflows And Tidal Debris, Javier Rodríguez Zaurín, Clive N. Tadhunter, David S.N. Rupke, Sylvain Veilleux, Henrik W.W. Spoon, Marco Chiaberge, Cristina Ramos Almeida, Dan Batcheldor, William B. Sparks
Aerospace, Physics, and Space Science Faculty Publications
We present new HST/ACS medium-and narrow-band images and optical Isaac Newton Telescope long-slit spectra of the merging system Mrk273. The HST observations sample the [OIII]λλ4959,5007 emission from the galaxy and the nearby continuum. These data were taken as a part of a larger study of ultraluminous infrared galaxies (ULIRGs) with the aim of investigating the importance of the warm, AGN induced outflows in such objects. The HST images show that the morphologies of the extended continuum and the ionised gas emission from the galaxy are decoupled, extending almost perpendicular to each other. In particular, we detect for the first time …
X-Ray Nuclear Activity In S4g Barred Galaxies: No Link Between Bar Strength And Co-Occurrent Supermassive Black Hole Fueling, Mauricio Cristernas, Trisha Mizusawa
X-Ray Nuclear Activity In S4g Barred Galaxies: No Link Between Bar Strength And Co-Occurrent Supermassive Black Hole Fueling, Mauricio Cristernas, Trisha Mizusawa
Aerospace, Physics, and Space Science Faculty Publications
Stellar bars can lead to gas inflow toward the center of a galaxy and stimulate nuclear star formation. However, there is no compelling evidence on whether they also feed a central supermassive black hole: by measuring the fractions of barred active and inactive galaxies, previous studies have yielded conflicting results. In this paper, we aim to understand the lack of observational evidence for bar-driven active galactic nucleus (AGN) activity by studying a sample of 41 nearby (d < 35 Mpc) barred galaxies from the Spitzer Survey for Stellar Structure in Galaxies. We use Chandra observations to measure nuclear 2–10 keV X-ray luminosities and estimate Eddington ratios, together with Spitzer 3.6 μm imaging to quantify the strength of the stellar bar in two independent ways: (1) from its structure, as traced by its ellipticity and boxiness, and (2) from its gravitational torque Qb, taken as the maximum ratio of the tangential force to the mean background radial force. In this way, rather than discretizing the presence of both stellar bars and nuclear activity, we are able to account for the continuum of bar strengths and degrees of AGN activity. We find nuclear X-ray sources in 31 out of 41 galaxies with median X-ray luminosity and Eddington ratio of LX = 4.3×1038 erg s−1 and Lbol/LEdd = 6.9×10−6, respectively, consistent with low-luminosity AGN activity. Including upper limits for those galaxies without nuclear detections, we find no significant correlation between any of the bar strength indicators and the degree of nuclear activity, irrespective of galaxy luminosity, stellar mass, Hubble type, or bulge size. Strong bars do not favor brighter or more efficient nuclear activity, implying that at least for the low-luminosity regime, supermassive black hole fueling is not closely connected to large-scale features.
Periodic Structure In The Megaparsec-Scale Jet Of Pks 0637-752, L. E.H. Godfrey, E. S. Perlman
Periodic Structure In The Megaparsec-Scale Jet Of Pks 0637-752, L. E.H. Godfrey, E. S. Perlman
Aerospace, Physics, and Space Science Faculty Publications
We present 18 GHz Australia Telescope Compact Array imaging of the megaparsec-scale quasar jet PKS 0637–752 with angular resolution ~0farcs58. We draw attention to a spectacular train of quasi-periodic knots along the inner 11'' of the jet, with average separation ~1.1 arcsec (7.6 kpc projected). We consider two classes of model to explain the periodic knots: those that involve a static pattern through which the jet plasma travels (e.g., stationary shocks) and those that involve modulation of the jet engine. Interpreting the knots as re-confinement shocks implies the jet kinetic power Q jet ~ 1046 erg s–1, but the constant …
A Method For Localizing Energy Dissipation In Blazars Using Fermi Variability, Amanda Dotson, Markos Georganopoulos, Demosthenes Kazanas, Eric S. Perlman
A Method For Localizing Energy Dissipation In Blazars Using Fermi Variability, Amanda Dotson, Markos Georganopoulos, Demosthenes Kazanas, Eric S. Perlman
Aerospace, Physics, and Space Science Faculty Publications
The distance of a Fermi-detected blazar γ-ray emission site from a supermassive black hole is a matter of active debate. Here we present a method for testing if the GeV emission of powerful blazars is produced within the subparsec-scale broad-line region (BLR) or farther out in the parsec-scale molecular torus (MT) environment If the GeV emission takes place within the BLR, the inverse Compton (IC) scattering of the BLR ultraviolet (UV) seed photons that produces the γ-rays takes place at the onset of the Klein–Nishina regime. This causes the electron cooling time to become practically energy-independent and the variation of …
A Multi-Wavelength Study Of The Jet, Lobes, And Core Of The Quasar Pks 2101-490, Leith E.H. Godfrey, Eric S. Perlman
A Multi-Wavelength Study Of The Jet, Lobes, And Core Of The Quasar Pks 2101-490, Leith E.H. Godfrey, Eric S. Perlman
Aerospace, Physics, and Space Science Faculty Publications
We present a detailed study of the x-ray, optical, and radio emission from the jet, lobes, and core of the quasar PKS 2101−490 as revealed by new Chandra, Hubble Space Telescope (HST), and ATCA images. We extract the radio to x-ray spectral energy distributions from seven regions of the 13'' jet, and model the jet x-ray emission in terms of Doppler beamed inverse Compton scattering of the cosmic microwave background (IC/CMB) for a jet in a state of equipartition between particle and magnetic field energy densities. This model implies that the jet remains highly relativistic hundreds of kiloparsecs from the …
The 2010 Very High Energy Y-Ray Flare And 10 Years Of Multi-Wavelength Observations Of M 87, A. Abramowski, Mihai Cara, Eric S. Perlman, The H.E.S.S. Collaboration, The Magic Collaboration
The 2010 Very High Energy Y-Ray Flare And 10 Years Of Multi-Wavelength Observations Of M 87, A. Abramowski, Mihai Cara, Eric S. Perlman, The H.E.S.S. Collaboration, The Magic Collaboration
Aerospace, Physics, and Space Science Faculty Publications
The giant radio galaxy M 87 with its proximity (16 Mpc), famous jet, and very massive black hole ((3 – 6) × 109 M ☉) provides a unique opportunity to investigate the origin of very high energy (VHE; E > 100 GeV) γ-ray emission generated in relativistic outflows and the surroundings of supermassive black holes. M 87 has been established as a VHE γ-ray emitter since 2006. The VHE γ-ray emission displays strong variability on timescales as short as a day. In this paper, results from a joint VHE monitoring campaign on M 87 by the MAGIC and VERITAS instruments in …
Optical Polarization And Spectral Variability In The M87 Jet, Eric S. Perlman, Mihai Cara, Matthew Bourque, Raymond C. Simons
Optical Polarization And Spectral Variability In The M87 Jet, Eric S. Perlman, Mihai Cara, Matthew Bourque, Raymond C. Simons
Aerospace, Physics, and Space Science Faculty Publications
During the last decade, M87's jet has been the site of an extraordinary variability event, with one knot (HST-1) increasing by over a factor 100 in brightness. Variability has also been seen on timescales of months in the nuclear flux. Here we discuss the optical-UV polarization and spectral variability of these components, which show vastly different behavior. HST-1 shows a highly significant correlation between flux and polarization, with P increasing from 20% at minimum to >40% at maximum, while the orientation of its electric vector stayed constant. HST-1's optical-UV spectrum is very hard (αUV-O 0.5, F ν ∞ ν-α), and …
Deep Multiwaveband Observations Of The Jets Of 0208-512 And 1202-262, Eric S. Perlman
Deep Multiwaveband Observations Of The Jets Of 0208-512 And 1202-262, Eric S. Perlman
Aerospace, Physics, and Space Science Faculty Publications
We present deep Hubble Space Telescope, Chandra, Very Large Array, and Australia Telescope Compact Array images of the jets of PKS 0208-512 and PKS 1202-262, which were found in a Chandra survey of a flux-limited sample of flat-spectrum radio quasars with jets. We discuss in detail their X-ray morphologies and spectra. We find optical emission from one knot in the jet of PKS 1202-262 and two regions in the jet of PKS 0208-512. The X-ray emission of both jets is most consistent with external Comptonization of cosmic microwave background photons by particles within the jet, while the optical emission is …
An X-Ray Imaging Survey Of Quasar Jets: Testing The Inverse Compton Model, Herman L. Marshall, Jonathan M. Gelbord, Daniel A. Schwartz, David W. Murphey, James E.J. Lovell, Diana M. Worrall, Mark Birkinshaw, Eric S. Perlman, Leith E.H. Godfrey, David L. Jauncey
An X-Ray Imaging Survey Of Quasar Jets: Testing The Inverse Compton Model, Herman L. Marshall, Jonathan M. Gelbord, Daniel A. Schwartz, David W. Murphey, James E.J. Lovell, Diana M. Worrall, Mark Birkinshaw, Eric S. Perlman, Leith E.H. Godfrey, David L. Jauncey
Aerospace, Physics, and Space Science Faculty Publications
We present results from continued Chandra X-ray imaging and spectroscopy of a flux-limited sample of flat spectrum radio-emitting quasars with jet-like extended structure. X-rays are detected from 24 of the 39 jets observed so far. We compute the distribution of αrx, the spectral index between the X-ray and radio bands, showing that it is broad, extending at least from 0.8 to 1.2. While there is a general trend that the radio brightest jets are detected most often, it is clear that predicting the X-ray flux from the radio knot flux densities is risky, so a shallow X-ray survey is the …
A Flare In The Jet Of Pictor A, Herman L. Marshall, Eric S. Perlman
A Flare In The Jet Of Pictor A, Herman L. Marshall, Eric S. Perlman
Aerospace, Physics, and Space Science Faculty Publications
A Chandra X-ray imaging observation of the jet in Pictor A showed a feature that appears to be a flare that faded between 2000 and 2002. The feature was not detected in a follow-up observation in 2009. The jet itself is over 150kpc long and about 1 kpc wide, so finding year-long variability is surprising. Assuming a synchrotron origin of the observed high-energy photons and a minimum energy condition for the outflow, the synchrotron loss time of the X-ray emitting electrons is of order 1200 years, which is much longer than the observed variability timescale. This leads to the possibility …
Hubble Space Telescope Near-Infrared Snapshot Survey Of 3cr Radio Source Counterparts. Iii. Radio Galaxies And Quasars In Context, David J.E. Floyd, David Axon, Stefi Baum, Alessandro Capetti, Marco Chiaberge, Juan P. Madrid, Christopher P. O'Dea, Eric S. Perlman, William B. Sparks
Hubble Space Telescope Near-Infrared Snapshot Survey Of 3cr Radio Source Counterparts. Iii. Radio Galaxies And Quasars In Context, David J.E. Floyd, David Axon, Stefi Baum, Alessandro Capetti, Marco Chiaberge, Juan P. Madrid, Christopher P. O'Dea, Eric S. Perlman, William B. Sparks
Aerospace, Physics, and Space Science Faculty Publications
We compare the near-infrared (NIR) H-band photometric and morphological properties of low-z (z < 0.3) 3CR radio galaxies with samples of BL Lac objects and quasar host galaxies, merger remnants, quiescent elliptical galaxies, and brightest cluster galaxies drawn from the literature. In general, the 3CR host galaxies are consistent with luminous (~Lsstarf) elliptical galaxies. The vast majority of FR II's (~80%) occupy the most massive ellipticals and form a homogeneous population that is comparable to the population of radio-loud quasar (RLQ) host galaxies in the literature. However, a significant minority (~20%) of the 3CR FR II's appears under-luminous with respect to quasar host galaxies. All FR II objects in this faint tail are either unusually red, or appear to be the brightest objects within a group. We discuss the apparent differences between the radio galaxy and RLQ host galaxy populations. RLQs appear to require gsim1011 M☉ host galaxies (and ~109 M☉ black holes), whereas radio galaxies and radio-quiet quasars can exist in galaxies down to ~3 × 1010 M☉. This may be due to biases in the measured quasar host galaxy luminosities or populations studied, or due to a genuine difference in host galaxy. If due to a genuine difference, it would support the idea that radio and optical active galactic nuclei are two separate populations with a significant overlap.
Chandra Observations Of The Radio Galaxy 3c 445 And The Hot Spot X-Ray Emission Mechanism, Eric S. Perlman, Markos Georganopoulos, Emily M. May, Deosthenes Kazanas
Chandra Observations Of The Radio Galaxy 3c 445 And The Hot Spot X-Ray Emission Mechanism, Eric S. Perlman, Markos Georganopoulos, Emily M. May, Deosthenes Kazanas
Aerospace, Physics, and Space Science Faculty Publications
We present new Chandra observations of the radio galaxy 3C 445, centered on its southern radio hot spot. Our observations detect X-ray emission displaced upstream and to the west of the radio-optical hot spot. Attempting to reproduce both the observed spectral energy distribution and the displacement excludes all one-zone models. Modeling of the radio-optical hot spot spectrum suggests that the electron distribution has a low-energy cutoff or break approximately at the proton rest mass energy. The X-rays could be due to external Compton scattering of the cosmic microwave background coming from the fast (Lorentz factor Γ ≈ 4) part of …
Chandra Observations Of The Radio Galaxy 3c 445 And The Hot Spot X-Ray Emission Mechanism, Eric S. Perlman, Markos Georganopoulos, Emily M. May, Demosthenes Kazanas
Chandra Observations Of The Radio Galaxy 3c 445 And The Hot Spot X-Ray Emission Mechanism, Eric S. Perlman, Markos Georganopoulos, Emily M. May, Demosthenes Kazanas
Aerospace, Physics, and Space Science Faculty Publications
We present new Chandra observations of the radio galaxy 3C 445, centered on its southern radio hot spot. Our observations detect X-ray emission displaced upstream and to the west of the radio-optical hot spot. Attempting to reproduce both the observed spectral energy distribution and the displacement excludes all one-zone models. Modeling of the radio-optical hot spot spectrum suggests that the electron distribution has a low-energy cutoff or break approximately at the proton rest mass energy. The X-rays could be due to external Compton scattering of the cosmic microwave background coming from the fast (Lorentz factor Γ ≈ 4) part of …
A Multi-Wavelength Spectral And Polarimetric Study Of The Jet Of 3c 264, Eric S. Perlman
A Multi-Wavelength Spectral And Polarimetric Study Of The Jet Of 3c 264, Eric S. Perlman
Aerospace, Physics, and Space Science Faculty Publications
We present a comprehensive multi-band spectral and polarimetric study of the jet of 3C 264 (NGC 3862). Included in this study are three Hubble Space Telescope (HST) optical and ultraviolet polarimetry data sets, along with new and archival Very Large Array radio imaging and polarimetry, a re-analysis of numerous HST broadband data sets from the near infrared to the far ultraviolet, and a Chandra ACIS-S observation. We investigate similarities and differences between optical and radio polarimetry, in both degree of polarization and projected magnetic field direction. We also examine the broadband spectral energy distribution of both the nucleus and jet …
Variability Timescales In The M87 Jet: Signatures Of E^2 Losses, Discovery Of A Quasi Period In Hst-1, And The Site Of Tev Flaring, Daniel E. Harris, Chi C. Cheung, Łukasz Stawarz, J. A. Biretta, Eric S. Perlman
Variability Timescales In The M87 Jet: Signatures Of E^2 Losses, Discovery Of A Quasi Period In Hst-1, And The Site Of Tev Flaring, Daniel E. Harris, Chi C. Cheung, Łukasz Stawarz, J. A. Biretta, Eric S. Perlman
Aerospace, Physics, and Space Science Faculty Publications
We investigate the variability timescales in the jet of M87 with two goals. The first is to use the rise times and decay times in the radio, ultraviolet, and X-ray light curves of HST-1 to constrain the source size and the energy loss mechanisms affecting the relativistic electron distributions. HST-1 is the first jet knot clearly resolved from the nuclear emission by Chandra and is the site of the huge flare of 2005. We find clear evidence for a frequency-dependent decrease in the synchrotron flux being consistent with E 2 energy losses. Assuming that this behavior is predominantly caused by …
A Multizone Model For Simulating The High-Energy Variability Of Tev Blazars, Philip B. Graff, Markos Georganopoulos, Eric S. Perlman, Demosthenes Kazanas
A Multizone Model For Simulating The High-Energy Variability Of Tev Blazars, Philip B. Graff, Markos Georganopoulos, Eric S. Perlman, Demosthenes Kazanas
Aerospace, Physics, and Space Science Faculty Publications
We present a time-dependent multizone code for simulating the variability of synchrotron self-Compton (SSC) sources. The code adopts a multizone pipe geometry for the emission region, appropriate for simulating emission from a standing or propagating shock in a collimated jet. Variations in the injection of relativistic electrons in the inlet propagate along the length of the pipe, cooling radiatively. Our code for the first time takes into account the nonlocal, time-retarded nature of SSC losses that are thought to be dominant in TeV blazars. The observed synchrotron and SSC emission is followed self-consistently, taking into account light-travel time delays. At …
A Novel Method For Measuring The Extragalactic Background Light: Fermi Application To The Lobes Of Fornax A, Markos Georganopoulos, Rita M. Sambruna, Demosthenes Kazanas, Analia N. Cillis, Chi C. Cheung, Eric S. Perlman, Katherine M. Blundell, David S. Davis
A Novel Method For Measuring The Extragalactic Background Light: Fermi Application To The Lobes Of Fornax A, Markos Georganopoulos, Rita M. Sambruna, Demosthenes Kazanas, Analia N. Cillis, Chi C. Cheung, Eric S. Perlman, Katherine M. Blundell, David S. Davis
Aerospace, Physics, and Space Science Faculty Publications
We describe a new method for measuring the extragalactic background light (EBL) through the detection of γ-ray inverse Compton (IC) emission due to scattering of the EBL photons off relativistic electrons in the lobes of radio galaxies. Our method has no free physical parameters and is a powerful tool when the lobes are characterized by a high-energy sharp break or cutoff in their electron energy distribution (EED). We show that such a feature will produce a high-energy IC “imprint” of the EBL spectrum in which the radio lobes are embedded and show how this imprint can be used to derive …
Hubble Space Telescope Near-Infrared Snapshot Survey Of 3cr Radio Source Counterparts. Ii. An Atlas And Inventory Of The Host Galaxies, Mergers, And Companions, David J. E. Floyd, Eric Perlman
Hubble Space Telescope Near-Infrared Snapshot Survey Of 3cr Radio Source Counterparts. Ii. An Atlas And Inventory Of The Host Galaxies, Mergers, And Companions, David J. E. Floyd, Eric Perlman
Aerospace, Physics, and Space Science Faculty Publications
We present the second part of an H-band (1.6 μm) "atlas" of z < 0.3 3CR radio galaxies, using the Hubble Space Telescope Near Infrared Camera and Multi-Object Spectrometer (HST NICMOS2). We present new imaging for 21 recently acquired sources and host galaxy modeling for the full sample of 101 (including 11 archival) - an 87% completion rate. Two different modeling techniques are applied, following those adopted by the galaxy morphology and the quasar host galaxy communities. Results are compared and found to be in excellent agreement, although the former breaks down in the case of sources with strong active galactic nuclei (AGNs). Companion sources are tabulated, and the presence of mergers, tidal features, dust disks, and jets are cataloged. The tables form a catalog for those interested in the structural and morphological dust-free host galaxy properties of the 3CR sample, and for comparison with morphological studies of quiescent galaxies and quasar host galaxies. Host galaxy masses are estimated and found to typically lie at around 2 × 1011 M⊙. In general, the population is found to be consistent with the local population of quiescent elliptical galaxies, but with a longer tail to low Sérsic index, mainly consisting of low-redshift (z < 0.1) and low-radio-power (FR I) sources. A few unusually disky FR II host galaxies are picked out for further discussion. Nearby external sources are identified in the majority of our images, many of which we argue are likely to be companion galaxies or merger remnants. The reduced NICMOS data are now publicly available from our Web site.