Mitigating Malmquist and Eddington Biases in Latent-Inclination Regression of the Tully-Fisher Relation

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The Tully-Fisher relation (TFR) is an empirical correlation between luminosities and rotation velocities of disk galaxies. Since rotation velocity can be measured independent of distance, this correlation allows astronomers to use disk galaxies as standardizable candles for distance measurements. Once the correlation is calibrated using distances from Cepheid variables in... [Read More]
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Building the Tully-Fisher Relation without Inclination Angles

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The Lucy statistical rectification method allows one to uncover the intrinsic distribution of data from its observed distribution. In this ApJ Letter, I apply the method to build the Tully-Fisher relation of disk galaxies, where both axes of the correlation (magnitude and emission line widths) are affected by the inclination... [Read More]
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A New Longslit Spectrograph for Undergraduate Astronomy Labs

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In Fall 2021 and Spring 2022, two undergraduate students helped me commission a longslit spectrograph on the 17-in telescope (PlaneWave CDK17) at the Van Allen Observatory (VAO). The LISA Spectrograph is made by Shelyak Instruments. The spectrograph bundle includes the spectrograph optics, a small CCD camera for target acquisition, a... [Read More]
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MaNGA Merger Project funded by the NSF (AST-2103251)

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The important role played by collisions and mergers in galaxy evolution has been appreciated since the 1970’s. Previous spectroscopic studies of colliding/merging galaxies, while confirming several basic predictions (e.g., elevated nuclear star formation and/or black hole accretion), generally explored only their brighter inner-most regions in a largely non-uniform manner. This... [Read More]
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Flat rotation curves measured in ancient dusty starburst galaxies

but they rotate more than 2x faster than the Milky Way

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This study utilizes extremely deep high-resolution data from the Atacama Large Millimeter / submillimeter Array (ALMA). Various molecules (e.g., water, carbon monoxide) are detected in a pair of dusty starburst galaxies called ‘HXMM01’, a mega-merger that occurred 10 billion years ago (see news story on Los Angeles Times). In both... [Read More]
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