Jason Pinkney | Ohio Northern University (original) (raw)
Papers by Jason Pinkney
The Astrophysical Journal, Dec 20, 2007
The largest galaxies, and in particular central galaxies in clusters, offer unique insight into u... more The largest galaxies, and in particular central galaxies in clusters, offer unique insight into understanding the mechanism for the growth of nuclear black holes. We present Hubble Space Telescope kinematics for NGC 1399, the central galaxy in Fornax. We find the best-fit model contains a black hole of (5:1 AE 0:7) ; 10 8 M (at a distance of 21.1 Mpc), a factor of over 2 below the correlation of black hole mass and velocity dispersion. We also find a dramatic signature for central tangential anisotropy. The velocity profiles on adjacent sides 0.5 00 away from the nucleus show strong bimodality, and the central spectrum shows a large drop in the dispersion. Both of these observations point to an orbital distribution that is tangentially biased. The best-fit orbital model suggests a ratio of the tangential to radial internal velocity dispersions of 3. This ratio is the largest seen in any galaxy to date and will provide an important measure for the mode by which the central black hole has grown.
American Astronomical Society Meeting Abstracts #235, 2020
American Astronomical Society Meeting Abstracts, Dec 1, 1999
The mass of a central black hole in a galaxy provides significant information concerning the evol... more The mass of a central black hole in a galaxy provides significant information concerning the evolution of the stellar system. We are involved in a program to determine these black-hole masses to high accuracy in nearby early-type galaxies using HST and ground-based spectroscopy. Pinkney et al. present the kinematic results for the present sample. We use a fully-general modeling program to estimate the mass without assuming a form for the stellar orbital distribution, and, hence, provide the current orbital structure of the stars near the center as well. We present the results for three galaxies, NGC821, NGC4473, and NGC4697. In both NGC821 and NGC4473, the data require a central massive black hole; models for NGC4697 are in progress. The measured stellar orbital distributions are characteristic of other galaxies studied with these general models, suggesting a common history amongst galaxies. We use the measured orbital structure to determine the dominant evolutionary processes that effect both the black-hole mass and the global galaxy structure. It appears that elliptical galaxy formation and evolution is intimately connected to the existence of a central massive black hole.
American Astronomical Society Meeting Abstracts #196, May 1, 2000
American Astronomical Society Meeting Abstracts, Dec 1, 1995
The Astronomical Journal, Nov 1, 2001
Galaxies that contain bulges appear to contain central black holes whose masses correlate with th... more Galaxies that contain bulges appear to contain central black holes whose masses correlate with the velocity dispersion of the bulge. We show that no corresponding relationship applies in the pure disk galaxy M 33. Threeintegral dynamical models fit Hubble Space Telescope WFPC2 photometry and STIS spectroscopy best if the central black hole mass is zero. The upper limit is 1500 M. This is significantly below the mass expected from the velocity dispersion of the nucleus and far below any mass predicted from the disk kinematics. Our results suggest that supermassive black holes are associated only with galaxy bulges and not with their disks.
Bulletin of the American Physical Society, Mar 23, 2018
Submitted for the OSS18 Meeting of The American Physical Society Stellar and gas kinematics in th... more Submitted for the OSS18 Meeting of The American Physical Society Stellar and gas kinematics in the lenticular galaxy NGC 3489 MATTHEW SIBILA, JASON PINKNEY, Ohio Northern University-We observed the S0 3 lenticular galaxy NGC 3489 using the B&C spectrograph on the Magellan I, 6.5-m telescope in 2001. The slit was not long enough to sample the sky spectrum without including galaxy light and so a new approach was developed for sky subtraction. We describe the approach elsewhere (see poster on NGC 7727) and report here on the findings for NGC 3489. The sky contamination in the NGC 3489 data was primarily airglow since it was observed in dark sky conditions. Our new sky subtraction method reveals that about half of the counts at the ends of the slit (R=35") are attributable to sky and the rest are galaxy. The absolute galaxy counts are greater than the other two galaxies presented here, improving the reliability of kinematics beyond 25". We measure stellar velocity dispersions significantly lower than Caon et al (2000) but consistent with the results of SAURON (Emsellem et al. 2004). Subtraction of a stellar template allows us to also measure gas kinematics in NGC 3489 from the residual [OIII] emission.
The Astrophysical Journal, Jan 10, 1997
We present new ROSAT PSPC X-ray pointed observations of nine Abell clusters that contain wideangl... more We present new ROSAT PSPC X-ray pointed observations of nine Abell clusters that contain wideangle tailed (WAT) radio galaxies. The sample of WAT clusters was selected from a VLA radio survey of the Abell catalog at 20 cm and the ROSAT All-Sky Survey (RASS). We found that up to eight (89%) clusters show some evidence of X-ray substructure. These clusters also have clear evidence of isophotal twisting, ellipticity variation, and isophote centroid variation as a function of distance from the central X-ray peak. Moreover, none of these WAT clusters have signiÐcant cluster-wide cooling Ñows in spite of the presence of dominant elliptical (radio) galaxies. We performed temperature Ðts to the X-ray emission by applying a Raymond-Smith Ðt to the spectra and a "" broadband ÏÏ temperature technique. One striking correlation with the radio sources was discovered : there is a strong relationship between the orientation of the WAT tails and the direction of X-ray elongations within the core of the clusters. We believe that this is consistent with WAT clusters undergoing mergers with groups or subclusters of galaxies. We compared our results with numerical hydro/N-body simulations of merging galaxy clusters to test this hypothesis. We found that the X-ray synthetic images generated by the simulations reproduce all the major morphological properties that we found in our sample. Furthermore, the simulations also show that the bulk Ñow of gas within the ICM present during the merger could be responsible for the correlation between the X-ray elongations and the direction of the bending of the radio tails.
Deep Blue (University of Michigan), 2011
We present Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph observations of the ... more We present Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph observations of the galaxy NGC 4382 (M85) and axisymmetric models of the galaxy to determine mass-to-light ratio (ϒ V) and central black hole mass (M BH). We find ϒ V = 3.74 ± 0.1 M /L and M BH = 1.3 +5.2 −1.2 × 10 7 M at an assumed distance of 17.9 Mpc, consistent with no black hole. The upper limit, M BH < 9.6 × 10 7 M (2σ) or M BH < 1.4 × 10 8 (3σ), is consistent with the current M-σ relation, which predicts M BH = 8.8 × 10 7 M at σ e = 182 km s −1 , but low for the current M-L relation, which predicts M BH = 7.8 × 10 8 M at L V = 8.9 × 10 10 L ,V. HST images show the nucleus to be double, suggesting the presence of a nuclear eccentric stellar disk, analogous to the Tremaine disk in M31. This conclusion is supported by the HST velocity dispersion profile. Despite the presence of this non-axisymmetric feature and evidence of a recent merger, we conclude that the reliability of our black hole mass determination is not hindered. The inferred low black hole mass may explain the lack of nuclear activity.
American Astronomical Society Meeting Abstracts, Dec 1, 1995
New X-ray observations are presented for 9 Abell clusters which contain wide-angle tailed (WAT) r... more New X-ray observations are presented for 9 Abell clusters which contain wide-angle tailed (WAT) radio galaxies. These clusters were observed with the PSPC on board the ROSAT observatory. The sample of WAT clusters was selected from a VLA radio survey of the Abell catalog at 20-cm and the ROSAT-all-sky-survey (RASS). We found an important correlation between the X-ray morphology and
Bulletin of the American Physical Society, Oct 19, 2007
Submitted for the OSF07 Meeting of The American Physical Society Gas and Stellar Kinematics in th... more Submitted for the OSF07 Meeting of The American Physical Society Gas and Stellar Kinematics in the Galaxy NGC 1961 BRIAN SACASH, JASON PINKNEY, Ohio Northern University-Long-slit spectroscopy and CCD imaging from the Hubble Space Telescope and the MDM Observatory is presented for the massive spiral galaxy NGC 1961. We intend to measure the mass of the central supermassive black hole (SMBH). We developed our own software for spectral extraction, and for the fitting of absorption and emission lines. The program subtracts the absorption-line (stellar) portion from the emission-line spectra using a shifted template star. This improves the measurements of the residual emission lines. We present our measurements of the line centroids (velocities), widths (velocity dispersions), and strengths for the most prominent emission lines (Hα, [NII], and [SII]). The rotation curve from the ground-based data is in good agreement with previous work by Rubin (1979); its asymmetric appearance suggests a possible merger. The emission lines near the nucleus broaden indicating some intrinsic dispersion. The central gas rotation curve at HST resolution is more complex than that expected for a cold, gas disk, confounding the measurement of a central black hole.
arXiv (Cornell University), Mar 10, 2004
We show that orbit-superposition dynamical models (Schwarzschild's method) provide reliable estim... more We show that orbit-superposition dynamical models (Schwarzschild's method) provide reliable estimates of nuclear black hole masses and errors when constructed from adequate orbit libraries and kinematic data. We thus rebut two recent papers that argue that BH masses obtained from this method are unreliable. These papers claim to demonstrate that the range of allowable BH masses derived from a given dataset is artificially too narrow as a result of an inadequate number of orbits in the library used to construct dynamical models. This is an elementary error that is easily avoided. We describe a method to estimate the number and nature of orbits needed for the library. We provide an example that shows that this prescription is adequate, in the sense that the range of allowable BH masses is not artificially narrowed by use of too few orbits. This is illustrated by showing that the χ 2 versus BH-mass curve does not change beyond a certain point as more orbits are added to the library. At that point, the phase-space coverage of the orbit library is good enough to estimate the BH mass, and the χ 2 profile provides a reliable estimate of its errors. A second point raised by critics is that kinematic data are generally obtained with insufficient spatial resolution (compared to the BH radius of influence) to obtain a reliable mass. We make the distinction between unreliable determinations and imprecise ones. We show that there are several different properties of a kinematic dataset that can lead to imprecise BH determinations (insufficient resolution among them), but none of the attributes we have investigated leads to an unreliable determination. In short, the degree to which the BH radius of influence is resolved by spectroscopic observations is already reflected in the BH-mass error envelope, and is not a hidden source of error. The BH masses published by our group and the Leiden group are reliable.
Bulletin of the American Physical Society, Apr 24, 2009
presented for the massive spiral galaxy NGC 1961. We aimed to measure the mass of the central sup... more presented for the massive spiral galaxy NGC 1961. We aimed to measure the mass of the central supermassive black hole (SMBH). We have developed our own software for spectral extraction and for the fitting of absorption and emission lines. The program subtracts the absorption-line (stellar) component from the emissionline spectra to improve the fidelity of our emission line measurements. We present our line centroids (velocities), widths (velocity dispersions), and strengths for the most prominent emission lines (Hα, [NII], and [SII]). The rotation curve from the ground-based data is in good agreement with previous work by Rubin (1979); its asymmetric appearance suggests a tidal interaction or merger. We use the rotation curve and surface photometry to estimate the enclosed mass profile of the galaxy. The emission lines near the nucleus broaden indicating more intrinsic dispersion than expected for a cold, gas disk. We estimate the BH mass using simple gas disk models. However, the high dispersion and the asymmetry in its inner rotation curve suggest that this approach is unreliable.
The Astronomical Journal, Dec 1, 1994
New x-ray, optical, and redshift data are presented for the cluster of galaxies associated with t... more New x-ray, optical, and redshift data are presented for the cluster of galaxies associated with the giant, 1 Mpc diameter, wide-angle tailed (WAT) radio galaxy 1919+479. The ROSAT Position-Sensitive Proportional Counter (PSPC) pointed observation shows an x-ray peak on the WAT and elongated diffuse emission tracing the galaxy distribution. In addition, an asymmetric extension of emission exists between the tails
Bulletin of the American Physical Society, Apr 15, 2011
Submitted for the OSS11 Meeting of The American Physical Society An investigation of the nuclear ... more Submitted for the OSS11 Meeting of The American Physical Society An investigation of the nuclear black hole mass and global properties of NGC 4552 PETER KIRCHER, JASON PINKNEY, Ohio Northern University-In previous papers, we presented the spectroscopic and photometric data needed to estimate the mass of the supermassive black hole in NGC 4552. Now we have a new, refined black hole mass estimate from gas disk kinematics. We plot our galaxy on the key demographic scaling relations of M BH vs. σ and M BH vs. Luminosity. Since black hole formation appears to be intertwined with galaxy formation, we also compare the global properties of our galaxy (effective radius, luminosity, effective surface brightness, ellipticity) to other galaxies, including views of the "fundamental plane." Our elliptical is relatively compact, low in ellipticity, with almost no rotational support and with a "core" surface brightness profile. We also consider the gas/dust morphology: NGC 4552 appears to be another galaxy with an erratic dust disk morphology which nevertheless produces an (apparently) accurate BH mass using gas kinematics.
Bulletin of the American Physical Society, Oct 4, 2013
Bulletin of the American Physical Society, Oct 4, 2013
(2007a). We wish to improve upon the accuracy of the velocity dispersions produced by the SDSS pi... more (2007a). We wish to improve upon the accuracy of the velocity dispersions produced by the SDSS pipeline. We use the ModSpec Spectrograph on the 2.4 Hiltner telescope at MDM Observatory. Our longslit spectra have a spectral range of about 4650 to 5650Å, which includes the MgB absorption lines and Hβ + [OIII] emission lines. We describe the reduction of the CCD spectra and the fitting of absorption and emission lines using the direct pixel fitting technique. We combine multiple exposures to improve S/N ratio, but the uncertainties in velocity dispersion remain > 8% because of template mismatch. Our stellar velocity dispersions are largely consistent with the SDSS results and they predict black hole masses around 10 6 M sol for most of our sample.
Bulletin of the American Physical Society, 2013
Submitted for the OSS13 Meeting of The American Physical Society Analysis of 2D substructure in r... more Submitted for the OSS13 Meeting of The American Physical Society Analysis of 2D substructure in radio-loud clusters of galaxies 1 DONALD PLESHINGER, JASON PINKNEY, Ohio Northern University-We have produced and refined catalogs of galaxy positions, magnitudes, colors and redshifts in ten, radio-loud clusters of galaxies. The CCD images were taken with the MOSA imager on the Kitt Peak 0.9-m telescope. We use the color-magnitude relation (CMR) in B-V and B-R to select samples of galaxies which are members of the targeted clusters. We also restrict the samples to galaxies within one Abell radius (for Ho=75 km/s/Mpc) of the center, using two approaches for defining the center. We estimate the contamination of the CMR samples by foreground and background galaxies to be about 10%. We apply four statistical tests for the significance of 2D (plain of the sky) substructure to all of the samples, and obtain significance levels using Monte Carlo simulations. We are able to rule out the null hypothesis of a unimodal distribution with confidence for the majority of clusters. Isopleth contour maps are used to verify the substructure qualitatively. This allows us to address our motivating question: do cluster-subcluster mergers have an influence on radio galaxy morphology?
The Astrophysical Journal, Dec 20, 2007
The largest galaxies, and in particular central galaxies in clusters, offer unique insight into u... more The largest galaxies, and in particular central galaxies in clusters, offer unique insight into understanding the mechanism for the growth of nuclear black holes. We present Hubble Space Telescope kinematics for NGC 1399, the central galaxy in Fornax. We find the best-fit model contains a black hole of (5:1 AE 0:7) ; 10 8 M (at a distance of 21.1 Mpc), a factor of over 2 below the correlation of black hole mass and velocity dispersion. We also find a dramatic signature for central tangential anisotropy. The velocity profiles on adjacent sides 0.5 00 away from the nucleus show strong bimodality, and the central spectrum shows a large drop in the dispersion. Both of these observations point to an orbital distribution that is tangentially biased. The best-fit orbital model suggests a ratio of the tangential to radial internal velocity dispersions of 3. This ratio is the largest seen in any galaxy to date and will provide an important measure for the mode by which the central black hole has grown.
American Astronomical Society Meeting Abstracts #235, 2020
American Astronomical Society Meeting Abstracts, Dec 1, 1999
The mass of a central black hole in a galaxy provides significant information concerning the evol... more The mass of a central black hole in a galaxy provides significant information concerning the evolution of the stellar system. We are involved in a program to determine these black-hole masses to high accuracy in nearby early-type galaxies using HST and ground-based spectroscopy. Pinkney et al. present the kinematic results for the present sample. We use a fully-general modeling program to estimate the mass without assuming a form for the stellar orbital distribution, and, hence, provide the current orbital structure of the stars near the center as well. We present the results for three galaxies, NGC821, NGC4473, and NGC4697. In both NGC821 and NGC4473, the data require a central massive black hole; models for NGC4697 are in progress. The measured stellar orbital distributions are characteristic of other galaxies studied with these general models, suggesting a common history amongst galaxies. We use the measured orbital structure to determine the dominant evolutionary processes that effect both the black-hole mass and the global galaxy structure. It appears that elliptical galaxy formation and evolution is intimately connected to the existence of a central massive black hole.
American Astronomical Society Meeting Abstracts #196, May 1, 2000
American Astronomical Society Meeting Abstracts, Dec 1, 1995
The Astronomical Journal, Nov 1, 2001
Galaxies that contain bulges appear to contain central black holes whose masses correlate with th... more Galaxies that contain bulges appear to contain central black holes whose masses correlate with the velocity dispersion of the bulge. We show that no corresponding relationship applies in the pure disk galaxy M 33. Threeintegral dynamical models fit Hubble Space Telescope WFPC2 photometry and STIS spectroscopy best if the central black hole mass is zero. The upper limit is 1500 M. This is significantly below the mass expected from the velocity dispersion of the nucleus and far below any mass predicted from the disk kinematics. Our results suggest that supermassive black holes are associated only with galaxy bulges and not with their disks.
Bulletin of the American Physical Society, Mar 23, 2018
Submitted for the OSS18 Meeting of The American Physical Society Stellar and gas kinematics in th... more Submitted for the OSS18 Meeting of The American Physical Society Stellar and gas kinematics in the lenticular galaxy NGC 3489 MATTHEW SIBILA, JASON PINKNEY, Ohio Northern University-We observed the S0 3 lenticular galaxy NGC 3489 using the B&C spectrograph on the Magellan I, 6.5-m telescope in 2001. The slit was not long enough to sample the sky spectrum without including galaxy light and so a new approach was developed for sky subtraction. We describe the approach elsewhere (see poster on NGC 7727) and report here on the findings for NGC 3489. The sky contamination in the NGC 3489 data was primarily airglow since it was observed in dark sky conditions. Our new sky subtraction method reveals that about half of the counts at the ends of the slit (R=35") are attributable to sky and the rest are galaxy. The absolute galaxy counts are greater than the other two galaxies presented here, improving the reliability of kinematics beyond 25". We measure stellar velocity dispersions significantly lower than Caon et al (2000) but consistent with the results of SAURON (Emsellem et al. 2004). Subtraction of a stellar template allows us to also measure gas kinematics in NGC 3489 from the residual [OIII] emission.
The Astrophysical Journal, Jan 10, 1997
We present new ROSAT PSPC X-ray pointed observations of nine Abell clusters that contain wideangl... more We present new ROSAT PSPC X-ray pointed observations of nine Abell clusters that contain wideangle tailed (WAT) radio galaxies. The sample of WAT clusters was selected from a VLA radio survey of the Abell catalog at 20 cm and the ROSAT All-Sky Survey (RASS). We found that up to eight (89%) clusters show some evidence of X-ray substructure. These clusters also have clear evidence of isophotal twisting, ellipticity variation, and isophote centroid variation as a function of distance from the central X-ray peak. Moreover, none of these WAT clusters have signiÐcant cluster-wide cooling Ñows in spite of the presence of dominant elliptical (radio) galaxies. We performed temperature Ðts to the X-ray emission by applying a Raymond-Smith Ðt to the spectra and a "" broadband ÏÏ temperature technique. One striking correlation with the radio sources was discovered : there is a strong relationship between the orientation of the WAT tails and the direction of X-ray elongations within the core of the clusters. We believe that this is consistent with WAT clusters undergoing mergers with groups or subclusters of galaxies. We compared our results with numerical hydro/N-body simulations of merging galaxy clusters to test this hypothesis. We found that the X-ray synthetic images generated by the simulations reproduce all the major morphological properties that we found in our sample. Furthermore, the simulations also show that the bulk Ñow of gas within the ICM present during the merger could be responsible for the correlation between the X-ray elongations and the direction of the bending of the radio tails.
Deep Blue (University of Michigan), 2011
We present Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph observations of the ... more We present Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph observations of the galaxy NGC 4382 (M85) and axisymmetric models of the galaxy to determine mass-to-light ratio (ϒ V) and central black hole mass (M BH). We find ϒ V = 3.74 ± 0.1 M /L and M BH = 1.3 +5.2 −1.2 × 10 7 M at an assumed distance of 17.9 Mpc, consistent with no black hole. The upper limit, M BH < 9.6 × 10 7 M (2σ) or M BH < 1.4 × 10 8 (3σ), is consistent with the current M-σ relation, which predicts M BH = 8.8 × 10 7 M at σ e = 182 km s −1 , but low for the current M-L relation, which predicts M BH = 7.8 × 10 8 M at L V = 8.9 × 10 10 L ,V. HST images show the nucleus to be double, suggesting the presence of a nuclear eccentric stellar disk, analogous to the Tremaine disk in M31. This conclusion is supported by the HST velocity dispersion profile. Despite the presence of this non-axisymmetric feature and evidence of a recent merger, we conclude that the reliability of our black hole mass determination is not hindered. The inferred low black hole mass may explain the lack of nuclear activity.
American Astronomical Society Meeting Abstracts, Dec 1, 1995
New X-ray observations are presented for 9 Abell clusters which contain wide-angle tailed (WAT) r... more New X-ray observations are presented for 9 Abell clusters which contain wide-angle tailed (WAT) radio galaxies. These clusters were observed with the PSPC on board the ROSAT observatory. The sample of WAT clusters was selected from a VLA radio survey of the Abell catalog at 20-cm and the ROSAT-all-sky-survey (RASS). We found an important correlation between the X-ray morphology and
Bulletin of the American Physical Society, Oct 19, 2007
Submitted for the OSF07 Meeting of The American Physical Society Gas and Stellar Kinematics in th... more Submitted for the OSF07 Meeting of The American Physical Society Gas and Stellar Kinematics in the Galaxy NGC 1961 BRIAN SACASH, JASON PINKNEY, Ohio Northern University-Long-slit spectroscopy and CCD imaging from the Hubble Space Telescope and the MDM Observatory is presented for the massive spiral galaxy NGC 1961. We intend to measure the mass of the central supermassive black hole (SMBH). We developed our own software for spectral extraction, and for the fitting of absorption and emission lines. The program subtracts the absorption-line (stellar) portion from the emission-line spectra using a shifted template star. This improves the measurements of the residual emission lines. We present our measurements of the line centroids (velocities), widths (velocity dispersions), and strengths for the most prominent emission lines (Hα, [NII], and [SII]). The rotation curve from the ground-based data is in good agreement with previous work by Rubin (1979); its asymmetric appearance suggests a possible merger. The emission lines near the nucleus broaden indicating some intrinsic dispersion. The central gas rotation curve at HST resolution is more complex than that expected for a cold, gas disk, confounding the measurement of a central black hole.
arXiv (Cornell University), Mar 10, 2004
We show that orbit-superposition dynamical models (Schwarzschild's method) provide reliable estim... more We show that orbit-superposition dynamical models (Schwarzschild's method) provide reliable estimates of nuclear black hole masses and errors when constructed from adequate orbit libraries and kinematic data. We thus rebut two recent papers that argue that BH masses obtained from this method are unreliable. These papers claim to demonstrate that the range of allowable BH masses derived from a given dataset is artificially too narrow as a result of an inadequate number of orbits in the library used to construct dynamical models. This is an elementary error that is easily avoided. We describe a method to estimate the number and nature of orbits needed for the library. We provide an example that shows that this prescription is adequate, in the sense that the range of allowable BH masses is not artificially narrowed by use of too few orbits. This is illustrated by showing that the χ 2 versus BH-mass curve does not change beyond a certain point as more orbits are added to the library. At that point, the phase-space coverage of the orbit library is good enough to estimate the BH mass, and the χ 2 profile provides a reliable estimate of its errors. A second point raised by critics is that kinematic data are generally obtained with insufficient spatial resolution (compared to the BH radius of influence) to obtain a reliable mass. We make the distinction between unreliable determinations and imprecise ones. We show that there are several different properties of a kinematic dataset that can lead to imprecise BH determinations (insufficient resolution among them), but none of the attributes we have investigated leads to an unreliable determination. In short, the degree to which the BH radius of influence is resolved by spectroscopic observations is already reflected in the BH-mass error envelope, and is not a hidden source of error. The BH masses published by our group and the Leiden group are reliable.
Bulletin of the American Physical Society, Apr 24, 2009
presented for the massive spiral galaxy NGC 1961. We aimed to measure the mass of the central sup... more presented for the massive spiral galaxy NGC 1961. We aimed to measure the mass of the central supermassive black hole (SMBH). We have developed our own software for spectral extraction and for the fitting of absorption and emission lines. The program subtracts the absorption-line (stellar) component from the emissionline spectra to improve the fidelity of our emission line measurements. We present our line centroids (velocities), widths (velocity dispersions), and strengths for the most prominent emission lines (Hα, [NII], and [SII]). The rotation curve from the ground-based data is in good agreement with previous work by Rubin (1979); its asymmetric appearance suggests a tidal interaction or merger. We use the rotation curve and surface photometry to estimate the enclosed mass profile of the galaxy. The emission lines near the nucleus broaden indicating more intrinsic dispersion than expected for a cold, gas disk. We estimate the BH mass using simple gas disk models. However, the high dispersion and the asymmetry in its inner rotation curve suggest that this approach is unreliable.
The Astronomical Journal, Dec 1, 1994
New x-ray, optical, and redshift data are presented for the cluster of galaxies associated with t... more New x-ray, optical, and redshift data are presented for the cluster of galaxies associated with the giant, 1 Mpc diameter, wide-angle tailed (WAT) radio galaxy 1919+479. The ROSAT Position-Sensitive Proportional Counter (PSPC) pointed observation shows an x-ray peak on the WAT and elongated diffuse emission tracing the galaxy distribution. In addition, an asymmetric extension of emission exists between the tails
Bulletin of the American Physical Society, Apr 15, 2011
Submitted for the OSS11 Meeting of The American Physical Society An investigation of the nuclear ... more Submitted for the OSS11 Meeting of The American Physical Society An investigation of the nuclear black hole mass and global properties of NGC 4552 PETER KIRCHER, JASON PINKNEY, Ohio Northern University-In previous papers, we presented the spectroscopic and photometric data needed to estimate the mass of the supermassive black hole in NGC 4552. Now we have a new, refined black hole mass estimate from gas disk kinematics. We plot our galaxy on the key demographic scaling relations of M BH vs. σ and M BH vs. Luminosity. Since black hole formation appears to be intertwined with galaxy formation, we also compare the global properties of our galaxy (effective radius, luminosity, effective surface brightness, ellipticity) to other galaxies, including views of the "fundamental plane." Our elliptical is relatively compact, low in ellipticity, with almost no rotational support and with a "core" surface brightness profile. We also consider the gas/dust morphology: NGC 4552 appears to be another galaxy with an erratic dust disk morphology which nevertheless produces an (apparently) accurate BH mass using gas kinematics.
Bulletin of the American Physical Society, Oct 4, 2013
Bulletin of the American Physical Society, Oct 4, 2013
(2007a). We wish to improve upon the accuracy of the velocity dispersions produced by the SDSS pi... more (2007a). We wish to improve upon the accuracy of the velocity dispersions produced by the SDSS pipeline. We use the ModSpec Spectrograph on the 2.4 Hiltner telescope at MDM Observatory. Our longslit spectra have a spectral range of about 4650 to 5650Å, which includes the MgB absorption lines and Hβ + [OIII] emission lines. We describe the reduction of the CCD spectra and the fitting of absorption and emission lines using the direct pixel fitting technique. We combine multiple exposures to improve S/N ratio, but the uncertainties in velocity dispersion remain > 8% because of template mismatch. Our stellar velocity dispersions are largely consistent with the SDSS results and they predict black hole masses around 10 6 M sol for most of our sample.
Bulletin of the American Physical Society, 2013
Submitted for the OSS13 Meeting of The American Physical Society Analysis of 2D substructure in r... more Submitted for the OSS13 Meeting of The American Physical Society Analysis of 2D substructure in radio-loud clusters of galaxies 1 DONALD PLESHINGER, JASON PINKNEY, Ohio Northern University-We have produced and refined catalogs of galaxy positions, magnitudes, colors and redshifts in ten, radio-loud clusters of galaxies. The CCD images were taken with the MOSA imager on the Kitt Peak 0.9-m telescope. We use the color-magnitude relation (CMR) in B-V and B-R to select samples of galaxies which are members of the targeted clusters. We also restrict the samples to galaxies within one Abell radius (for Ho=75 km/s/Mpc) of the center, using two approaches for defining the center. We estimate the contamination of the CMR samples by foreground and background galaxies to be about 10%. We apply four statistical tests for the significance of 2D (plain of the sky) substructure to all of the samples, and obtain significance levels using Monte Carlo simulations. We are able to rule out the null hypothesis of a unimodal distribution with confidence for the majority of clusters. Isopleth contour maps are used to verify the substructure qualitatively. This allows us to address our motivating question: do cluster-subcluster mergers have an influence on radio galaxy morphology?