01/06/2022
New Flight Plan for January 6:
2022 January 6-7 Flight Plan OC9I IRWIN
(Note that “NGC” designates objects in the New General Catalog, a 19th-century British catalog of non-stellar objects such as nebulas and galaxies.)
Leg 6 (66 mins): R-90.1+190.2 (d ~ 31 million light-years)
Proposal ID = 08_0183 PI = J.D. Smith (Univ. of Toledo, Ohio)
Target is the central region of relatively nearby face-on spiral galaxy NGC 628 a.k.a. Messier 74. The name appears to designate a particular radio source within the galaxy.
https://en.wikipedia.org/wiki/Messier_74
Leg 7 (91 mins): NGC 595 (d ~ 2.7 million light-years)
Proposal ID = 09_0023 PI = Tucker Jones (Univ. of California - Davis)
Target is a large star forming region in the nearby galaxy M33 a.k.a. the Triangulum Galaxy.
https://en.wikipedia.org/wiki/NGC_595
https://en.wikipedia.org/wiki/Triangulum_Galaxy
Leg 8 (64 mins): NGC 6946_Nucleus (d ~ 25 million light-years)
Proposal ID = 09_0198 PI = Cody Lamarche (Univ. of Toledo, Ohio)
Target is the nucleus of the nearby spiral galaxy NGZC 6946 a.k.a. the Fireworks Galaxy.
https://en.wikipedia.org/wiki/NGC_6946
Leg 10 (125 mins): NGC 4848 (d ~ 340 million light-years)
Proposal ID = 09_0221 PI = Ming Sun (Univ. of Alabama, Huntsville)
NGC 4848 is an exceptionally large barred spiral galaxy.
https://en.wikipedia.org/wiki/NGC_4848
Leg 11 (72 mins): II SZ010 (d ~ 480 million light-years)
Proposal ID = 08_0226 PI = Andreea Petric (Univ. of Hawai`i)
Target is a relatively nearby quasar, a supermassive black hole in a galaxy nucleus.
https://en.wikipedia.org/wiki/Quasar
Leg 12 (39 mins): NGC 3125 (d ~ 50 million light-years)
Proposal ID = 09_0023 PI = Tucker Jones (Univ. of California - Davis)
Target is a large star-forming region in galaxy NGC 3125.
https://www.nasa.gov/image-feature/goddard/2016/hubble-views-a-galaxy-fit-to-burst
Program proposal abstracts in numerical order
Proposal ID: 08_0183
Principal Investigator: J.D. Smith (University of Toledo)
Title: Unlocking Far-Infrared Metal Abundances in NGC628
Abstract: Elements heavier than helium make up only a small fraction of the mass of the present day Universe, yet they heavily impact how galaxies and stars form and evolve. The chemical enrichment history of the Universe therefore forms an essential part of any complete understanding of galaxy evolution. The ground-state fine structure of the abundant metals oxygen and nitrogen which are accessible to SOFIA in the far-infrared will play a major role in uncovering this history. [OIII] 88µm is already the highest redshift line ever detected in a galaxy (z=9.1), and both potential future FIR missions SPICA and Origins feature the rise of metals as a chief science case. With the ability to pe*****te large columns of obscuration in the dusty galaxies that dominate the peak epoch of star formation, and little sensitivity to the unknown temperature structure of ionized nebulae that has plagued traditional optical strong line metal abundances for decades, FIR abundances offer many powerful advantages. Yet substantial work is still needed locally to take full advantage of this potential. We propose a pilot study of the well-studied galaxy NGC628, targeting a dozen regions drawn from the CHAOS program on the LBT -- the largest, deepest survey of direct spectroscopic optical auroral line metal abundances ever undertaken in the local Universe. Combining SOFIA/FIFI-LS with CHAOS spectroscopy, archival Herschel/PACS and Spitzer/IRS, and even VLA free-free continuum observations of carefully selected regions in NGC628, we will fully develop several interrelated temperature insensitive infrared abundance tools, including direct [OIII] abundances normalized to hydrogen using recombination or free-free emission, and expand and validate the novel O3N3 pure FIR-line abundance relationship. Our ancillary data also include deep optical IFU spectral mapping data, to bridge the resolution divide between the SOFIA and ground-optical surveys.
Proposal ID: 08_0226
Principal Investigator: Andreea Petric (Institute for Astronomy, U. Hawai`i)
Title: Star-formation efficiencies in nearby, optically luminous Quasars
Abstract: Most bulge-dominated galaxies have at their centers black holes with masses that tightly correlate with the masses of their hosts' bulges. This may indicate that the black holes may regulate galaxy growth, or vice versa, or that they may grow in lock-step. The quest to understand how, when, and where those black-holes formed motivates much of extragalactic astronomy. The [CII] 157.74 micron fine structure line of singly ionized carbon has been calibrated both as a measure of star-formation rates and as a way to estimate the star-formation efficiencies. Recent SOFIA observations of [CII] in nearby low-luminosity AGN suggest that: high ratios of [CII] to FIR may be associated with obscured AGN outflows and that the [CIII] may be at the interface between warm and cold gas in those outflows. The observations we propose here will test whether luminous, obscured AGN have higher [CII]/FIR ratios than luminous, non-obscured AGN.
Proposal ID: 09_0023
Principal Investigator: Tucker Jones (University of California - Davis)
Title: Accurate chemical abundance measurements: from z=0 to the reionization epoch
Abstract: The gas-phase metallicity of galaxies encodes information about current and past gas inflows, outflows, and star formation. Accordingly, obtaining accurate metallicity measurements for large samples of galaxies is a major goal of galaxy formation and evolution studies. However, current results suffer from large systematic uncertainty in the absolute metallicity scale, revealed by disagreement between different direct measurement techniques. This disagreement can plausibly be explained by fluctuations in the gas temperature within HII regions, but an independent test is needed to determine whether this is indeed the case. We propose to use the unique capabilities of FIFI-LS onboard SOFIA to obtain measurements of the diagnostic [OIII] 52 um emission line for a sample of carefully-selected local HII regions with high-quality optical spectra. The addition of [OIII] 52 um data will provide an independent determination of the magnitude of temperature fluctuations and the absolute metallicity scale. The results will have an immediate benefit of eliminating the dominant systematic uncertainty in metallicity measurements of >100,000 galaxies at z=0 and >1,000 at z>1. Furthermore, these measurements will provide the framework necessary to combine ALMA measurements of far-IR lines with JWST rest-optical spectra to determine accurate metallicities at z>6 in the epoch of reionization. We will simultaneously observe the [CII] 158 um line to aid in understanding extremely high far-IR [OIII]/[CII] ratios found for z>6 galaxies using ALMA.
Principal Investigator: Cody Lamarche (University of Toledo)
Title: Securing Far-Infrared Metal Abundances in NGC 6946
Abstract: Elements heavier than helium contribute less than one percent to the total mass of the local Universe, yet they significantly affect the way in which stars and galaxies form and evolve. Therefore, understanding the chemical enrichment history of the Universe is an essential part of understanding galaxy evolution. The ground-state fine-structure levels of the abundant metals oxygen and nitrogen, accessible to SOFIA in the far-infrared, will play a major role in uncovering this history. With the ability to pe*****te the significant dust columns present in galaxies during the peak epoch of cosmic star formation, and little sensitivity to the unknown temperature structure of ionized nebulae that has plagued traditional optical strong-line metal-abundances for decades, FIR abundances offer many powerful advantages. Yet substantial work is still needed locally before these FIR methods can be extended to high-redshift galaxies. We propose a program to study NGC 6946, a bright, metal-rich, nearby spiral galaxy, targeting 8 HII regions that will be observed in concert with the ongoing CHAOS program on the LBT -- the largest, deepest survey of direct spectroscopic optical auroral-line metal-abundances ever undertaken in the local Universe. Combining SOFIA/FIFI-LS with CHAOS spectroscopy, archival Herschel/PACS and Spitzer/IRS, and VLA free-free continuum observations of the targeted HII regions in NGC 6946, we will explore several interrelated temperature-insensitive infrared abundance tools, including direct [OIII] abundances normalized to hydrogen using recombination or free-free emission, and expand and validate the novel O3N3 pure FIR-line abundance diagnostic. Our ancillary data also include deep optical IFU spectral mapping data, which bridge the resolution divide between the SOFIA and ground-based optical surveys.
Proposal ID: 09_0221
Principal Investigator: Ming Sun (University of Alabama in Huntsville)
Title: [C II] in the cluster galaxies undergoing ram pressure stripping
Abstract: Ram pressure stripping (RPS) is an important process in galaxy evolution. Recent multi-wavelength data have revealed many examples of galaxies undergoing RPS, often accompanied with multi-phase tails. As energy transfer in multi-phase medium is an outstanding question in astrophysics, important for e.g., galaxy formation and AGN feedback, RPS galaxies provide great examples to address the significant questions in multi-phase medium and star formation. [C II] has been established as an important tracer of the cold gas and star formation. However, there has not been a systematical study for the [C II] emission from RPS galaxies (especially their tails). On the other hand, we do know that [C II] emission can be enhanced by additional pressure from shocks, turbulence and collisional heating, which is ubiquitous in RPS galaxies. We propose SOFIA/FIFI-LS observations on five galaxies in the Coma cluster and A1367 for the first sample study for the [C II] emission from galaxies undergoing strong RPS. The [C II] data will be combined with the FIR, CO and Halpha data for multi-wavelength diagnostics and study. We will examine whether [C II] emission is enhanced in galaxies undergoing strong RPS and search for [C II] emission in the tails. [O I] from galaxies is also expected to provide additional constraints. We emphasize that the proposed science can only be done by SOFIA now and has never been tried before. Luckily, this is still within SOFIA's reach!
This NASA/ESA Hubble Space Telescope image reveals the vibrant core of the galaxy NGC 3125. Discovered by John Herschel in 1835, NGC 3125 is a great example of a starburst galaxy — a galaxy in which unusually high numbers of new stars are forming, springing to life within intensely hot clouds of g...