Dirk Grupe

Emergence of a Broad-Absorption-Line Outflow in the Narrow-line Seyfert 1 Galaxy WPVS 007 (2009)

Leighly, Karen M., Hamann, Fred, Casebeer, Darrin A., Grupe, Dirk

We report results from a 2003 FUSE observation, and reanalysis of a 1996 HST observation of the unusual X-ray transient Narrow-line Seyfert 1 galaxy WPVS 007. The HST FOS spectrum revealed mini-BALs...

Late-time detections of the X-ray afterglow of GRB 060729 with Chandra - the latest detections ever of an X-ray afterglow (2009)

Grupe, Dirk, Burrows, David N., Wang, Xiang-Yu, Zhang, Bing, Garmire, Gordon, ...

We report on 5 Chandra observations of the X-ray afterglow of the Gamma-Ray Burst GRB 060729 performed between 2007 March and 2008 May. In all five observations the afterglow is clearly detected. The...

Black Hole Masses of Intermediate-Redshift Quasars: Near Infrared Spectroscopy (2009)

Dietrich, Matthias, Mathur, Smita, Grupe, Dirk, Komossa, S.

We present near-infrared spectra of ten luminous, intermediate redshift quasars observed with SofI at the NTT of ESO/La Silla. With these rest-frame optical spectra we probe the Hb -[OIII] emission...

First detection of hard X-ray photons in the soft X-ray transient Narrow-Line Seyfert 1 galaxy WPVS 007: The X-ray photon distribution observed by Swift (2008)

Grupe, Dirk, Leighly, Karen M., Komossa, Stefanie

We report on the first detection of hard X-ray photons (E>2.5 keV) in the X-ray transient Narrow-Line Seyfert 1 galaxy WPVS 007 which was the AGN with the softest X-ray spectrum during the ROSAT...

GRB 060605: multi-wavelength analysis of the first GRB observed using integral field spectroscopy (2008)

Ferrero, Patrizia, Klose, Sylvio, Kann, David Alexander, Savaglio, Sandra, Schulze, Steve, Palazzi, Eliana, ...

The long and relatively faint gamma-ray burst GRB 060605 detected by \emph{Swift}/BAT lasted about 20 sec. Its afterglow could be observed with \emph{Swift}/XRT for nearly 1 day, while...

XMM-Newton observations of the Narrow-Line Seyfert 1 galaxy Mrk 335 in an historical low X-ray flux state (2008)

Grupe, Dirk, Komossa, Stefanie, Gallo, Luigi C., Fabian, Andrew C., Larsson, Josefin, Pradhan, Anil K., ...

We report the discovery of strong soft X-ray emission lines and a hard continuum above 2 keV in the Narrow-Line Seyfert 1 galaxy Mrk 335 during an extremely low X-ray flux state. Mrk 335 was observed...

Discovery of the Narrow-Line Seyfert 1 galaxy Mkn 335 in an historical low X-ray flux state (2007)

Grupe, Dirk, Komossa, Stefanie, Gallo, Luigi

We report the discovery of the Narrow-Line Seyfert 1 galaxy Mkn 335 in an extremely low X-ray state. A comparison of Swift observations obtained in May and June/July 2007 with all previous X-ray...

An Update on the X-ray transient Narrow-Line Seyfert 1 galaxy WPVS 007: Swift observations of UV variability and persistence of X-ray faintness (2007)

Grupe, Dirk, Schady, Patricia, Leighly, Karen M., Komossa, Stefanie, O'Brien, Paul, Nousek, John A.

We report on the detection of UV variability and the persistence of X-ray faintness of the X-ray transient Narrow-Line Seyfert 1 galaxy WPVS 007 based on the first year of monitoring this AGN with...

Redshift Filtering by Swift Apparent X-ray Column Density (2006)

Grupe, Dirk, Nousek, John A., Berk, Daniel E. Vanden, Roming, Peter W. A., Burrows, David N., Godet, Olivier, ...

We remark on the utility of an observational relation between the absorption column density in excess of the Galactic absorption column density, $\Delta N_{\rm H} = N_{\rm H, fit} - N_{\rm H, gal}$,...

Revisiting the Black Hole Masses of Soft X-ray-Selected Active Galactic Nuclei (2006)

Watson, Linda C., Mathur, Smita, Grupe, Dirk

In our previous work, using luminosity and the H-beta FWHM as surrogates for black hole mass (M_BH), we compared the black hole masses of narrow-line Seyfert 1 galaxies (NLS1s) and broad-line Seyfert...

The Intrinsically X-ray Weak Quasar PHL 1811. I. X-ray Observations and Spectral Energy Distribution (2006)

Leighly, Karen M., Halpern, Jules P., Jenkins, Edward B., Grupe, Dirk, Choi, Jiehae, Prescott, Kimberly B.

This is the first of two papers reporting observations and analysis of the unusually bright (m_b=14.4), luminous (M_B=-25.5), nearby (z=0.192) narrow-line quasar PHL 1811, focusing on the X-ray...

Swift and XMM-Newton Observations of the Extraordinary GRB 060729: An afterglow with a more than 100 days X-ray light curve (2006)

Grupe, Dirk, Gronwall, Caryl, Wang, Xiang-Yu, Roming, Peter, Cummings, Jay, Zhang, Bing, ...

We report the results of the Swift and XMM observations of the Swift-discovered long Gamma-Ray Burst GRB 060729 ($T_{90}$=115s). The afterglow of this burst was exceptionally bright in X-rays as well...

GRB Radiative Efficiencies Derived from the Swift Data: GRBs vs. XRFs, Long vs. Short (2006)

Zhang, Bing, Liang, Enwei, Page, Kim L., Grupe, Dirk, Zhang, Bin-Bin, Barthelmy, Scott D., ...

We systematically analyze the prompt emission and the early afterglow data of a sample of 31 GRBs detected by {\em Swift} before September 2005, and estimate the GRB radiative efficiency. BAT's...

The early X-ray emissions from GRBs (2006)

O'Brien, Paul T., Willingale, R., Osborne, Julian P., Goad, Michael R., Page, Kim L., Vaughan, Simon, ...

The definitive version of this paper, with enhancements, is available from http://www.journals.uchicago.edu/ApJ/journal/issues/ApJ/v647n2/64315/64315.html

Testing the curvature effect and internal origin of gamma-ray burst prompt emissions and X-ray flares with Swift data (2006)

Liang, E.W., Zhang, B., O'Brien, Paul T., Willingale, R., Angelini, Lorella, Burrows, David N., ...

The definitive version of this paper, with enhancements, is available from http://www.journals.uchicago.edu/ApJ/journal/issues/ApJ/v646n1/64620/64620.html

The Swift X-ray flaring afterglow of GRB 050607 (2006)

Pagani, Claudio, Morris, David C., Kobayashi, Shiho, Sakamoto, Takanori, Falcone, Abraham D., Moretti, Alberto, ...

The definitive version of this paper is available at http://www.journals.uchicago.edu/ApJ/journal/issues/ApJ/v645n2/64323/64323.html

Jet Breaks in Short Gamma-Ray Bursts. II: The Collimated Afterglow of GRB 051221A (2006)

Burrows, David N., Grupe, Dirk, Capalbi, Milvia, Panaitescu, Alin, Patel, Sandeep K., Kouveliotou, Chryssa, ...

We report the best evidence to date of a jet break in a short Gamma-Ray Burst (GRB) afterglow, using Chandra and Swift XRT observations of the X-ray afterglow of GRB 051221A. The combined X-ray light...

The Swift X-ray flaring afterglow of GRB 050607 (2006)

Pagani, Claudio, Morris, David C., Kobayashi, Shiho, Sakamoto, Takanori, Falcone, Abraham D., Moretti, Alberto, ...

The unique capability of the Swift satellite to perform a prompt and autonomous slew to a newly detected Gamma-Ray Burst (GRB) has yielded the discovery of interesting new properties of GRB X-ray...

Swift Observations of the highly X-ray variable Narrow Line Seyfert 1 galaxy RX J0148.3-2758 (2006)

Grupe, Dirk, Leighly, Karen M., Komossa, Stefanie, Schady, Patricia, O'Brien, Paul T., Burrows, Davis N., ...

We report on Swift observations of the Narrow-Line Seyfert 1 galaxy (NLS1) RX J0148.3--2758. It was observed for 41.6 ks in 2005 May and for 15.8 ks in 2005 December. On short as well as on long...

Swift Observations of GRB 050603: An afterglow with a steep late time decay slope (2006)

Grupe, Dirk, Brown, Peter, Cummings, Jay, Zhang, Bing, Retter, Alon, Burrows, David N., ...

We report the results of Swift observations of the Gamma Ray Burst GRB 050603. With a V magnitude V=18.2 about 10 hours after the burst the optical afterglow was the brightest so far detected by...

The Locus of Highly Accreting AGNs on the M_BH--sigma Plane: Selections, Limitations, and Implications (2005)

Mathur, Smita, Grupe, Dirk

We re-examine the locus of narrow line Seyfert 1 galaxies on the M_BH--sigma (black hole mass--bulge velocity dispersion) plane in the light of the results from large new optically selected samples....

Studying the Variation of the Fine Structure Constant Using Emission Line Multiplets (2005)

Grupe, Dirk, Pradhan, Anil K., Frank, Stephan

As an extension of the method by Bahcall et al. (2004) to investigate the time dependence of the fine structure constant, we describe an approach based on new observations of forbidden line...

An XMM-Newton Observation of the Seyfert 2 Galaxy NGC 6300. I. The Nucleus (2004)

Matsumoto, Chiho, Nava, Aida, Maddox, Larry A., Leighly, Karen M., Grupe, Dirk, Awaki, Hisamitsu, ...

We present results from a half-day observation by XMM-Newton of the nucleus of the nearby Seyfert 2 galaxy NGC 6300. The X-ray spectrum of the nucleus consists of a heavily absorbed hard component...

Black hole growth by accretion (2004)

Mathur, Smita, Grupe, Dirk

We show that black holes grow substantially by accretion at close to Eddington rates. Using a complete sample of soft X-ray selected AGNs, Grupe & Mathur (2004) have shown that narrow line Seyfert 1...

Black Hole Growth & the M_BH--Bulge Relations (2004)

Mathur, Smita, Grupe, Dirk

We present the black hole mass--bulge velocity dispersion relation for a complete sample of 75 soft X-ray selected AGNs. We find that the AGNs with highest accretion rates relative to Eddington lie...

M-BH - sigma relation for a Complete Sample of Soft X-ray Selected AGNs (2003)

Grupe, Dirk, Mathur, Smita

We present black hole mass--bulge velocity dispersion relation for a complete sample of 75 soft X-ray selected AGNs: 43 broad line Seyfert 1s and 32 narrow line Seyfert 1s. We use luminosity and...

Statistical Properties of Narrow-Line Seyfert 1 galaxies (2000)

Grupe, Dirk

The number of publications considering Narrow-Line Seyfert 1 galaxies has increased dramatically in recent years. Especially after the launch of the X-ray missions ROSAT and ASCA, Narrow-Line Seyfert...

The Optical Polarization and Warm Absorber in IRAS 17020+4544 (1997)

Leighly, Karen M., Kay, Laura E., Wills, Beverley J., Wills, D., Grupe, Dirk

We report the detection of ionized absorption in the ASCA spectrum of the narrow-line Seyfert 1 galaxy IRAS 17020+4544. Subsequent optical spectropolarimetry revealed high polarization increasing...