Miles Blanton | Bowling Green State University (original) (raw)
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Papers by Miles Blanton
We present the results of a VLA search for HI absorption in a sample of 24 radio loud ellipticals... more We present the results of a VLA search for HI absorption in a sample of 24 radio loud ellipticals with compact cores. The sample consists of sources with a core flux larger than 100 mJy and lie within a redshift range of z= 0.01 to 0.1. With an angular resolution of 1 arcsec and a velocity resolution of 42 km/s we reach typical 5 sigma limits in optical depths of 0.01. We detect at least five of the 24 sources in HI absorption. In some of these the HI absorption is spatially resolved and we will present the kinematic structure. We will combine our results with those of previous searches and discuss the detection statistics and kinematics of the gas.
We present a Ku-band (14GHz) GBT map of the walls of the Galactic Center Lobe (GCL): a 1-deg wide... more We present a Ku-band (14GHz) GBT map of the walls of the Galactic Center Lobe (GCL): a 1-deg wide, Ω-shaped, superwind bubble feature first discovered and mapped (at 10GHz) by Sofue (1985). The GCL consists primarily of two walls extending to the galactic north above the Galactic Plane, centered around (l,b)=(-0.3,+0.5). Our 14GHz map shows resolved features not observed in lower-frequency maps. These features are generally consistent with the brightness distribution of Sofue's original map, as well as the Bonn 2 and 5GHz survey maps. However, our new image differs from earlier images in some important details: first, Sofue's 10GHz map shows that the East wall (l=+0.2) is consistently brighter than the West wall (l=-0.6). At 14GHz, the walls are observed to have several knots or hotspots resulting in periodic brightening and dimming of the East wall relative to the West wall (as a function of increasing galactic latitude). Second, there is a very distinct filamentary structure between the East and West walls that is not present in Sofue's map. Third, we find that there is bridge connecting the East and West walls at b=+0.35 that is not observed in other maps. Indeed, our high-resolution map shows a plethora of filamentary and compact structures not observed in previous maps.
Outflows from nuclear winds are observed in dozens of galaxies and can have profound effects on g... more Outflows from nuclear winds are observed in dozens of galaxies and can have profound effects on galactic evolution and the state of the intergalactic medium. Nuclear winds may have different origin mechanisms, such as starbursts or accretion on the central engine, but regardless of how the energy is deposited into the nucleus, outflow from the expansion of very hot gas can result in a wind-blown superbubble. Periods of previous outflow in our own Galaxy have resulted in several structures interpreted as superbubbles; the Galactic Center Lobe (GCL), a 150pc-scale open, omega-shaped projection perpendicular to the Galactic Plane, more-or-less centered on the Galactic Center, is one such structure. We have observed the GCL at 14GHz (2cm) with the Robert C. Byrd 100m Green Bank Telescope (GBT) with the original intent to obtain a more definitive constraint on the energetics of the GCL, but in the course of our observations have concluded that the 'walls' of the GCL itself are composed of two likely unrelated structures. We reduce and analyze new GBT data with new software and use a novel filtering technique to analyze existing multi-band data from the Nobeyama Radio Observatory 45m telescope, the NRAO Very Large Array, the Spitzer Space Telescope, and the Chandra X-ray Observatory. We propose that the nuclear outflow is manifested not in both spurs of the GCL, but in the western spur of the GCL and a new structure observed above the SgrB-complex. Additionally, the eastern wall of the GCL is interpreted as a jet-like extension of the Galactic Center Arc, and is seen to be interacting with the Double Helix Nebula in a manner inconsistent with a limb-brightened shell wall.
We present the results of a VLA search for HI absorption in a sample of 24 radio loud ellipticals... more We present the results of a VLA search for HI absorption in a sample of 24 radio loud ellipticals with compact cores. The sample consists of sources with a core flux larger than 100 mJy and lie within a redshift range of z= 0.01 to 0.1. With an angular resolution of 1 arcsec and a velocity resolution of 42 km/s we reach typical 5 sigma limits in optical depths of 0.01. We detect at least five of the 24 sources in HI absorption. In some of these the HI absorption is spatially resolved and we will present the kinematic structure. We will combine our results with those of previous searches and discuss the detection statistics and kinematics of the gas.
We present a Ku-band (14GHz) GBT map of the walls of the Galactic Center Lobe (GCL): a 1-deg wide... more We present a Ku-band (14GHz) GBT map of the walls of the Galactic Center Lobe (GCL): a 1-deg wide, Ω-shaped, superwind bubble feature first discovered and mapped (at 10GHz) by Sofue (1985). The GCL consists primarily of two walls extending to the galactic north above the Galactic Plane, centered around (l,b)=(-0.3,+0.5). Our 14GHz map shows resolved features not observed in lower-frequency maps. These features are generally consistent with the brightness distribution of Sofue's original map, as well as the Bonn 2 and 5GHz survey maps. However, our new image differs from earlier images in some important details: first, Sofue's 10GHz map shows that the East wall (l=+0.2) is consistently brighter than the West wall (l=-0.6). At 14GHz, the walls are observed to have several knots or hotspots resulting in periodic brightening and dimming of the East wall relative to the West wall (as a function of increasing galactic latitude). Second, there is a very distinct filamentary structure between the East and West walls that is not present in Sofue's map. Third, we find that there is bridge connecting the East and West walls at b=+0.35 that is not observed in other maps. Indeed, our high-resolution map shows a plethora of filamentary and compact structures not observed in previous maps.
Outflows from nuclear winds are observed in dozens of galaxies and can have profound effects on g... more Outflows from nuclear winds are observed in dozens of galaxies and can have profound effects on galactic evolution and the state of the intergalactic medium. Nuclear winds may have different origin mechanisms, such as starbursts or accretion on the central engine, but regardless of how the energy is deposited into the nucleus, outflow from the expansion of very hot gas can result in a wind-blown superbubble. Periods of previous outflow in our own Galaxy have resulted in several structures interpreted as superbubbles; the Galactic Center Lobe (GCL), a 150pc-scale open, omega-shaped projection perpendicular to the Galactic Plane, more-or-less centered on the Galactic Center, is one such structure. We have observed the GCL at 14GHz (2cm) with the Robert C. Byrd 100m Green Bank Telescope (GBT) with the original intent to obtain a more definitive constraint on the energetics of the GCL, but in the course of our observations have concluded that the 'walls' of the GCL itself are composed of two likely unrelated structures. We reduce and analyze new GBT data with new software and use a novel filtering technique to analyze existing multi-band data from the Nobeyama Radio Observatory 45m telescope, the NRAO Very Large Array, the Spitzer Space Telescope, and the Chandra X-ray Observatory. We propose that the nuclear outflow is manifested not in both spurs of the GCL, but in the western spur of the GCL and a new structure observed above the SgrB-complex. Additionally, the eastern wall of the GCL is interpreted as a jet-like extension of the Galactic Center Arc, and is seen to be interacting with the Double Helix Nebula in a manner inconsistent with a limb-brightened shell wall.