Swift Mission Operation Center

State College, PA, United States

Swift Mission Operation Center

State College, PA, United States
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Wehrle A.E.,Space Science Institute | Grupe D.,Morehead State University | Grupe D.,Swift Mission Operation Center | Jorstad S.G.,Boston University | And 9 more authors.
Astrophysical Journal | Year: 2016

BL Lac, the eponymous blazar, flared to historically high levels at millimeter, infrared, X-ray, and gamma-ray wavelengths in 2012. We present observations made with Herschel, Swift, NuSTAR, Fermi, the Submillimeter Array, CARMA, and the VLBA in 2012-2013, including three months with nearly daily sampling at several wavebands. We have also conducted an intensive campaign of 30 hr with every-orbit observations by Swift and NuSTAR, accompanied by Herschel, and Fermi observations. The source was highly variable at all bands. Time lags, correlations between bands, and the changing shapes of the spectral energy distributions can be explained by synchrotron radiation and inverse Compton emission from nonthermal seed photons originating from within the jet. The passage of four new superluminal very long baseline interferometry knots through the core and two stationary knots about 4 pc downstream accompanied the high flaring in 2012-2013. The seed photons for inverse Compton scattering may arise from the stationary knots and from a Mach disk near the core where relatively slow-moving plasma generates intense nonthermal radiation. The 95 spectral energy distributions obtained on consecutive days form the most densely sampled, broad wavelength coverage for any blazar. The observed spectral energy distributions and multi-waveband light curves are similar to simulated spectral energy distributions and light curves generated with a model in which turbulent plasma crosses a conical shock with a Mach disk. © 2016. The American Astronomical Society. All rights reserved.


Foschini L.,National institute for astrophysics | Berton M.,University of Padua | Caccianiga A.,National institute for astrophysics | Ciroi S.,University of Padua | And 30 more authors.
Astronomy and Astrophysics | Year: 2015

We have conducted a multiwavelength survey of 42 radio loud narrow-1ine Seyfert 1 galaxies (RLNLS1s), selected by searching among all the known sources of this type and omitting those with steep radio spectra. We analyse data from radio frequencies to X-rays, and supplement these with information available from online catalogues and the literature in order to cover the full electromagnetic spectrum. This is the largest known multiwavelength survey for this type of source. We detected 90% of the sources in X-rays and found 17% at γ rays. Extreme variability at high energies was also found, down to timescales as short as hours. In some sources, dramatic spectral and flux changes suggest interplay between a relativistic jet and the accretion disk. The estimated masses of the central black holes are in the range ∼106-8 M⊙, lower than those of blazars, while the accretion luminosities span a range from ∼l0.01 to ∼l0.49 times the Eddington limit, with an outlier at 0.003, similar to those of quasars. The distribution of the calculated jet power spans a range from ∼l1042.6 to ∼l1045.6 erg s-1, generally lower than quasars and BL Lac objects, but partially overlapping with the latter. Once normalised by the mass of the central black holes, the jet power of the three types of active galactic nuclei are consistent with each other, indicating that the jets are similar and the observational differences are due to scaling factors. Despite the observational differences, the central engine of RLNLS1s is apparently quite similar to that of blazars. The historical difficulties in finding radio-loud narrow-line Seyfert 1 galaxies might be due to their low power and to intermittent jet activity. © ESO, 2015.


Schimoia J.S.,Federal University of Rio Grande do Sul | Schimoia J.S.,Ohio State University | Storchi-Bergmann T.,Federal University of Rio Grande do Sul | Storchi-Bergmann T.,Harvard - Smithsonian Center for Astrophysics | And 12 more authors.
Astrophysical Journal | Year: 2015

Recent studies have suggested that the short-timescale (≲7 days) variability of the broad (∼10,000 km s-1) double-peaked Hα profile of the LINER nucleus of NGC 1097 could be driven by a variable X-ray emission from a central radiatively inefficient accretion flow. To test this scenario, we have monitored the NGC 1097 nucleus in X-ray and UV continuum with Swift and the Hα flux and profile in the optical spectrum using SOAR and Gemini-South from 2012 August to 2013 February. During the monitoring campaign, the Hα flux remained at a very low level - three times lower than the maximum flux observed in previous campaigns and showing only limited (∼20%) variability. The X-ray variations were small, only ∼13% throughout the campaign, while the UV did not show significant variations. We concluded that the timescale of the Hα profile variation is close to the sampling interval of the optical observations, which results in only a marginal correlation between the X-ray and Hα fluxes. We have caught the active galaxy nucleus in NGC 1097 in a very low activity state, in which the ionizing source was very weak and capable of ionizing just the innermost part of the gas in the disk. Nonetheless, the data presented here still support the picture in which the gas that emits the broad double-peaked Balmer lines is illuminated /ionized by a source of high-energy photons which is located interior to the inner radius of the line-emitting part of the disk. © 2015. The American Astronomical Society. All rights reserved.


Parker M.L.,Institute of Astronomy | Schartel N.,Institute of Astronomy | Schartel N.,Newton Science Operations Center | Komossa S.,Max Planck Institute for Radio Astronomy | And 5 more authors.
Monthly Notices of the Royal Astronomical Society | Year: 2014

We present two new XMM-Newton observations of an unprecedented low-flux state in the Seyfert 1 Mrk 1048 (NGC 985), taken in 2013. The X-ray flux below 1 keV drops by a factor of 4-5, whereas the spectrum above 5 keV is essentially unchanged. This points towards an absorption origin for the low state, and we confirm this with spectral fitting, finding that the spectral differences can be well modelled by the addition of a partial covering neutral absorber, with a column density of ~3 × 1022 cm-2 and a covering fraction of ~0.6. The optical and UV fluxes are not affected, and indeed are marginally brighter in the more recent observations, suggesting that only the inner regions of the disc are affected by the absorption event. This indicates either that the absorption is due to a cloud passing over the inner disc, obscuring the X-ray source but leaving the outer disc untouched, or that the absorber is dust-free so the UV continuum is unaffected.We use arguments based on the duration of the event and the physical properties of the absorber to constrain its size and location, and conclude that it is most likely a small cloud at ~1018 cm from the source. © 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.


Yao S.,CAS National Astronomical Observatories | Yuan W.,CAS National Astronomical Observatories | Komossa S.,CAS National Astronomical Observatories | Komossa S.,Max Planck Institute for Radio Astronomy | And 4 more authors.
Proceedings of the International Astronomical Union | Year: 2016

1H 0323+342 is one of the rare γ-ray detected narrow-line Seyfert 1 galaxies (NLS1s), a special subset of active galactic nuclei (AGN) owing to their hybrid behavior of both NLS1s and blazars. The rarity of such kind of sources makes their properties far from being understood. We analyze simultaneous X-ray and UV/optical monitoring observations of 1H 0323+342 performed by Swift over ∼7 years. The UV/X-ray correlation and the broad band SED reveal that the X-ray band is dominated by the disk/corona emission during the observations. The large normalized excess variance of the X-ray variability detected with Suzaku suggests a relatively small black hole mass of the order of 107 M⊙, consistent with the estimation based on the broad Hβ line in the optical band. Copyright © 2016 International Astronomical Union.


Yao S.,CAS National Astronomical Observatories | Yuan W.,CAS National Astronomical Observatories | Komossa S.,CAS National Astronomical Observatories | Komossa S.,Max Planck Institute for Radio Astronomy | And 4 more authors.
Astronomical Journal | Year: 2015

As a radio-loud narrow-line Seyfert 1 galaxy (NLS1) detected by Fermi/LAT in GeV γ-rays, 1H 0323+342 is a remarkable active galactic nucleus showing properties characteristic of both NLS1s and blazars. Here we present results of simultaneous X-ray and UV/optical monitoring observations on 1H 0323+342 taken with the UV/Optical Telescope and X-ray Telescope onboard the Swift satellite over six years from 2006. Overall, the object showed statistically correlated variations in both the UV and X-ray bands on timescales of years as well as on timescales of days. A deep Suzaku observation reveals X-ray variability on timescales as short as a few tens of thousand seconds, and an X-ray spectrum typical of Seyfert galaxies. The broadband spectral energy distribution, for which the data of UV and X-ray observations taken on 2009 July 26-27 were used, can be well modeled with a simple one-zone leptonic jet model plus accretion disk/corona emission. The latter is predominantly responsible for the UV/optical and X-ray (0.3-10 keV) emission and their observed variations. The correlated UV-X-ray variability on the timescale of days is consistent with reprocessing of the X-ray radiation by the accretion disk. The shortest timescale and large normalized excess variance of the X-ray variability detected with Suzaku suggest a relatively small black hole mass of the order of 107 M, consistent with the estimation based on the broad Hβ line in the optical. © 2015. The American Astronomical Society. All rights reserved.


Komossa S.,Max Planck Institute for Radio Astronomy | Xu D.,CAS National Astronomical Observatories | Fuhrmann L.,Max Planck Institute for Radio Astronomy | Grupe D.,Morehead State University | And 8 more authors.
Astronomy and Astrophysics | Year: 2015

Aims. Radio-loud narrow-line type 1 galaxies provide us with a fresh look at the blazar phenomenon, the causes of radio loudness, and the physics of jet formation. We present a multi-wavelength study of the radio-loud narrow-line type 1 quasar RX J2314.9+2243, which exhibits some remarkable multi-wavelength properties. It is among the few radio-loud narrow-line type 1 galaxies, with a tentative γ-ray detection, is luminous in the infrared, and shows an exceptionally broad and blueshifted [OIII]λ5007 emission-line component. Methods. In order to understand the nature of this source, we have obtained optical, UV, X-ray, and radio observations of RX J2314.9+2243. Results. Its spectral energy distribution (SED) shows a broad hump extending between the IR and far-UV, a steep radio spectrum and flat X-ray spectrum. Its IR to far-UV SED is consistent with a scenario, in which synchrotron emission from a jet dominates the broadband emission, even though an absorption scenario cannot yet be fully excluded. The high blueshift of its very broad [OIII] component, 1260 km s-1, is consistent with a face-on view, with the jet (and outflow) pointing towards us. RX J2314.9+2243 likely represents an extreme case of AGN induced feedback in the local universe. © 2015 ESO.


Grupe D.,Swift Mission Operation Center | Grupe D.,Pennsylvania State University | Nousek J.A.,Swift Mission Operation Center | Nousek J.A.,Pennsylvania State University | And 4 more authors.
Astrophysical Journal, Supplement Series | Year: 2013

When a massive star explodes as a gamma-ray burst (GRB), information about the explosion is retained in the properties of the prompt and afterglow emission. We report on new relations between the prompt and X-ray afterglow emission of Swift-detected GRBs found from Burst Alert Telescope (BAT) and X-Ray Telescope data covering 2004 December to 2013 August (754 in total). These relations suggest that the prompt and afterglow emission are closely linked. In particular, we find very strong correlations between the BAT 15-150 keV T 90 and the break times before and after the plateau phase in the 0.3-10 keV X-ray afterglow light curves. We also find a strong anticorrelation between the photon index of the GRB prompt emission and the X-ray spectral slope of the afterglow. Moreover, anticorrelations exist between the rest-frame peak energy in the prompt emission E peak, z and the X-ray afterglow decay slope during the plateau phase and the break times after the plateau phase. The rest- frame break times before and after the plateau phase are also anticorrelated with the rest-frame 15-150 keV luminosity and the isotropic energy during the prompt emission. A principal component analysis suggests that the GRB properties are primarily driven by the luminosity/energy release in the 15-150 keV band. Luminosity functions derived at different redshifts from a log N-log S analysis indicate that the density of bright bursts is significantly lower in the local universe than in the universe at z ≈ 3, where the density of bright GRBs peaks. Using cluster analysis, we find that the duration of BAT-detected short GRBs is less than 1 s. We also present a catalog of all Swift onboard-detected bursts. © 2013. The American Astronomical Society. All rights reserved.

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