Special Events and Activities

Monday, January 9

Press Conference: Eyes on Galaxies with JWST

Phil Appleton (Caltech/IPAC-Euclid)

10:15 to 11 am PT

Room 307/308

Dr. Appleton will discuss the results from his ALMA/JWST observations of Stephan's Quintet. This press conference complements his AAS 241 science talk scheduled for 3:20 pm PT Thursday (448.08).

Plenary: Towards an Exoplanet Demographics Ladder: The Emerging Picture of Planet Populations

Jessie Christiansen (Caltech/IPAC-NASA Exoplanet Science Institute)

11:40 am to 12:30 pm PT

Ballroom 6E

In 2022 the NASA Exoplanet Archive passed 5,000 confirmed exoplanets. These planets and systems have been discovered with a variety of different techniques, each of which is sensitive to different populations of planets and comes with its own detection biases. However, a complete census of inner and outer planetary systems is slowly beginning to emerge. In this talk I will explore the parameter space probed by each technique, how and where the observed planet and stellar populations overlap, and how we might expand on previous work to exploit those overlaps and produce a new exoplanet demographics ladder. I will highlight expected upcoming significant contributions to exoplanet demographics, including from the ESA Gaia and NASA Roman missions. Finally, I will also highlight upcoming needs for robust exoplanet demographics, including preparation for the future flagship direct imaging mission.

Astroquery/PyVO Office Hours/Meetup

Brigitta Sipöcz (Caltech/IPAC) & Tom Donaldson (STScI)

4:30 to 6:30 pm PT

Caltech IPAC Booth 615, Exhibit Hall

Do you have an issue, concern, feature request, or idea related to Astroquery or PyVO? Here's a chance to chat with the people who maintain them! Come to the IPAC booth for an informal chat, or just to say hello.

Tuesday, January 10

NITARP Posters On Display at Caltech IPAC Booth

Exhbit Hall Booth 608

In case you miss the one-hour iPoster sessions for any of the NITARP science and education posters, the printed versions will be on display all day on Tuesday at the Caltech IPAC booth in the Exhibit Hall. Members of the 2022 NITARP teams will also be present. Stop by, say hello, and check out their work!

Nancy Grace Roman Space Telescope (Town Hall)

6:30 to 7:30 pm PT, Room 618/619

The Nancy Grace Roman Space Telescope (formerly known as WFIRST) is a NASA flagship mission planned for launch in the mid 2020s. The Roman Space Telescope will perform breakthrough science in dark energy cosmology, exoplanet microlensing, and NIR sky surveys with its Wide Field Instrument. Roman will also feature the Coronagraph Instrument (CGI), a technology demonstration that will directly image and take spectra of exoplanetary systems using several novel technologies together for the first time in space. This session will cover the status of the project and upcoming opportunities for community involvement in planning and executing the science and technology demonstration aspects of Roman. For more information please see: https://roman.gsfc.nasa.gov/AAS240.

Workshops

Using Python and Astropy for Astronomical Data Analysis

Sunday, Jan. 8, 9 am to 5:30 pm PT

Seattle Convention Center, Room 401

David Shupe (Caltech/IPAC), Kristen Larson (Western Washington University), Nadia Dencheva (STScI), Brett Morris (STScI), Larry Bradley (STScI), Leo Singer (NASA-GSFC), Nathaniel Starkman (U. of Toronto)

This workshop will cover the use of Python tools for astronomical data analysis and visualization, with the focus primarily on tools in the Astropy library and its affiliated packages. The goal is to introduce participants to the variety of tools which are available inside the Astropy library, and to provide time for participants to explore the science analysis capabilities which the scientific Python ecosystem and community provide. The format will include short presentations followed by instructor-guided tutorials where participants will use the tools and be able to ask questions in the company of expert users and developers.

We will first introduce the core Astropy package including units, quantities, and constants; coordinates; FITS, ASCII and Astropy tables; an introduction to object-oriented programming using lightcurves as the example data structure; images and their visualization; modeling; and other sub-packages. Then we may cover a few coordinated packages such as CCD image reduction (ccdproc), photometry (photutils), and spectroscopy (specutils).

Participants must bring a laptop with software installed, or be willing to use a Binder session in the cloud. We can support Mac OS X, Linux, and Windows 10+ operating systems. Support for Windows machines will require the Windows Subsystem for Linux (WSL; see https://docs.microsoft.com/en-us/windows/wsl/). In-person participants needing installation help can come early to the workshop room to receive assistance.

The workshop materials will be presented using Jupyter notebooks. The workshop repository is https://github.com/astropy/astropy-workshop.

Prerequisites: Some familiarity with Python and Numpy will be helpful but is not required. We will send some suggested tutorials before the workshop for those with no prior Python experience. Some familiarity with git and Github will be useful for installing the workshop software on your own computer, though we will try to minimize the need for those tools.

Accessing NASA's Astrophysics Archives using Python

Sunday, Jan. 8, 9 am to noon PT

Seattle Convention Center, Room 201 / 202

Brigitta Sipöcz (Caltech/IPAC), Xiuqin Wu (Caltech/IPAC-NED), Tess Jaffe (NASA-GSFC), Tom Donaldson (STScI)

NASA's astrophysics archives preserve many terabytes of multi-wavelength images, catalogs, and spectra. While many astronomers are familiar with web-based tools that are convenient for searching and visualizing these data, programmatic interfaces through Python are increasingly in demand. This hands-on workshop will introduce participants to the programmatic data access tools available and the tutorial notebooks we offer. Note that we use NASA data in our examples, but the tools and methods are generic. We will describe science scenarios that combine multi-wavelength data from the HEASARC, IRSA, NED, and MAST that participants will then be encouraged to work through themselves. Workshop organizers will be available to help participants with them or adapt them for custom projects.

Talks and Splinters

Monday, January 9

Nearby Galaxies Under a New Light with Roman (Splinter)

1 to 3 pm PT, Room 304

The Roman Space Telescope will provide HST-like spatial resolution in the optical and near-infrared, but with a field of view 100 times larger than HST. Even for single pointings, this provides data sets comparable to large survey projects with previous generation space-based observatories. Roman's large field-of-view will also quickly map the most nearby galaxies with resolved stars. Its superb astrometric capabilities will allow us to measure galaxy growth across space and time with unprecedented detail. Complementary, studies that map stellar populations with Roman in the most nearby galaxies will teach us valuable lessons to connect to observations and simulations of the early Universe. ALMA and JWST studies of galaxies probe the build-up of stellar mass at high redshift and, in complement, Roman will provide statistically significant samples to study how efficient metal production is during the most vigorous stages of galactic growth. The goal of this session is to bring together expertise from the local and more distant Universe to articulate how studies of the expanding horizon of the nearby Universe, with Roman, can be connected to our understanding of the most distant objects.

153.08 Early Results of Early Galaxies from JWST Early Release Programs

Takahiro Morishita (Caltech/IPAC)

3:10 to 3:20 pm PT, Room 2B

The James Webb Space Telescope (JWST) offers unprecedented sensitivities and spatial resolution in near- and mid-infrared wavelengths. Among nearly 300 science programs scheduled in Cycle 1, there are 13 programs that were pre-selected in a category called the Early Release Science (ERS). These programs are designed to advance the community’s understanding and early use of data from this new observatory, and thus all data taken therein have been/will be released immediately without a proprietary period. The Grism Lens-Amplified Survey from Space (GLASS) is one of the ERS programs, targeting Abell 2744, a massive cluster of galaxies at z = 0.308. In this presentation, we present the overview of our program and early results with three instruments, NIRISS, NIRSPEC, and NIRCam, focusing on spectroscopic identification and characterization of z > 7 galaxies through gravitational lensing by the cluster and identification of high-redshift galaxies in the parallel field.

Tuesday, January 10

UVCANDELS: completing Hubble's legacy in the CANDELS fields

Session Chair: Harry Teplitz (Caltech/IPAC-Euclid)

2 to 3:30 pm PT, Room 611

UVCANDELS is a cycle-26 Treasury Program that acquired 164 orbits of F275W+F435W imaging in four CANDELS fields: GOODS-N, GOODS-S, EGS, and COSMOS, covering a total area of ~430 square arcminutes and reaching a 5-sigma depth of 27 ABmag in F275W and 28 ABmag in F435W. The UVCANDELS team plans to release the catalog of UV+B measurements, together with photometric redshifts in early 2023. This unique dataset enables a range of science investigations, and provides a lasting archival legacy for future research. Hubble's UV imaging capability is unique, with no plan for a mission in the coming decade that can offer the combination of depth and spatial resolution. This special session will review highlights of science results by the UVCANDELS team, including: the growth of galaxy structure as revealed by star forming clumps; the quenching of star forming galaxies; the star formation history of Milky Way-like progenitors; the evolution of the UV spectral slope; and the UV galaxy luminosity function. In addition, we will familiarize the community with UVCANDELS data products that may be useful for planning future observations.

Wednesday, January 11

312.04 How Can Astronomers Make The Best Use of Cloud Platforms? (Keynote talk at the Special Session on Astronomy and Cloud Computing)

G. Bruce Berriman (Caltech/IPAC-NExScI)

10:40 to 11 am PT, Room 605/610

Cloud computing represents a new way of purchasing computing services rather than a technological advance: pay only for services used, in a similar fashion to the operating model for a public utility. Such a model offers in principle many benefits to the scientific community: on-demand access to up to-date compute and storage that can scale ("burst") as needed; democratized access to computing and storage at scale; reduction in the footprint of crowded on-premises computer rooms, elimination of on-premises system maintenance, and potential reduction in operating costs.

Despite the apparent simplicity of its business model, cloud computing has proven a highly disruptive business whose benefits are yet to be fully realized and whose full impact has yet to be felt. Among the reasons for this are: fine-grained metering of compute resources, storage and network in commercial platforms makes the economics difficult to manage and can lead to excessive and unanticipated costs instead of cost savings, especially for egress of large volumes of data; and explosion in services and the proliferation of providers can lead to "decision paralysis."

Despite problems such as the above, the astronomy community has been successfully investigating how to take advantage of cloud platforms in the past few years. Software advances such as "Infrastructure as Code" ( configuration files and machine-readable scripts that can be used to provision cloud infrastructure) and containers have made deployment and maintenance of processing environments on cloud platforms simpler than before. Investigations into the economics of cloud services are revealing best practices in managing costs, including large organizations negotiating contracted rates. With these considerations in mind, this talk will focus on how projects such as the Rubin Observatory, the MAST archive at Space Telescope, the Ice Cube Neutrino Observatory, and the Event Horizon Telescope and others are exploiting cloud platforms. The talk will also illustrate cloud usage in other disciplines. The projects above all create massive data products at scale. Researchers in smaller scale projects can take advantage of the cloud too, machine learning for example, and the talk will describe examples of such.

347.05 Spectroscopy of TOI-2318 A and B: Towards Precise Radii, Masses, and Bulk Densities of Planets in Multi-Star Systems

Catherine Clark (Caltech/IPAC)

2:40 to 2:50 pm PT

Nearly half of planet-hosting stars are binary, and this stellar multiplicity can have a dynamical influence on planet formation processes in the system. Precise stellar properties yield precise planet properties, and provide a window into planet formation and evolution in multi-star systems. However, few studies have determined both radii and masses, and thus bulk densities, for planets in multi-star systems. Consequently, planets in multi-star systems are not well-understood. Planet radius uncertainty is currently limited by the precision on the stellar radius, and in multi-star systems, stellar parameters are often biased by the presence of the stellar companion. To address this, we obtained spectra for both components of the binary star system TOI-2318, which are separated by 0.44'', with the AO-fed PARVI spectrograph. With a spatial resolution of 0.08'' in H, PARVI can observe stellar components as close as a few au for the nearest stellar systems. Our spectra of TOI-2318 A and B, combined with accurate Gaia parameters, allow us to establish the stellar parameters for each component to ~10%. These spectra also allow us to determine activity, rotation, component spectral types, and which star in the binary system hosts the orbiting planet. This pilot program is the start of a long-term, multi-instrument study to obtain bulk density measurements at the ~3 sigma level, with the intention to understand how planet formation and evolution may differ between single- and multi-star systems.

Starting Now: Community-led Definition of the Roman Core Community Surveys (Splinter)

2 to 3 pm PT, Room 4C-3

The Nancy Grace Roman Space Telescope's Wide Field Instrument (WFI) will have a large field of view (0.28 sq deg), Hubble-like sensitivity and resolution, and blistering survey speeds: the Roman Space Telescope will be capable of performing the equivalent of Hubble's largest surveys roughly 1000 times faster. Roman's WFI observing program will include both Core Community Surveys and General Astrophysics surveys, defined by a combination of a community-led process and traditional peer-reviewed calls for proposals, respectively. The Core Community Surveys (CCSs) will include a High Latitude Wide Area survey, a High Latitude Time Domain survey, and a Galactic Bulge Time Domain survey. In addition to addressing the Roman Mission's science requirements related to cosmology and exoplanet demographics, the data from the CCSs will enable a host of general astrophysical investigations.

The Roman Mission is intent on engaging the broad astronomical community in defining the CCSs in a way that will maximize their expansive scientific impact. This effort is starting now, with a call for white papers from the community planned for release in late 2022. The goal of the white paper call is to solicit from the community descriptions of specific scientific investigations that can be achieved with the CCSs, the observational strategies that will enable these investigations to be performed with a given CCS, and the figures of merit that can be used to assess whether an observational strategy will enable a particular investigation. The purpose of this special session is to provide attendees the information they need to write effective white papers, and to receive feedback from attendees on the planned community process for defining the CCSs. The session will include updates on the status of the Mission relevant to defining the core surveys, an overview of the community-driven process for defining the CCSs, a discussion of the observational parameter spaces under consideration for each CCS, a question and answer session, and the opportunity to provide feedback. Attendees will obtain the information necessary to produce informative, influential white papers, which in turn will be used to guide community-led definition of the observing strategies of the three Roman Core Community Surveys. Attendance of this splinter will be your first step to help ensure that Roman will obtain its survey data in a manner that is optimal for your science interests.

345.04 JWST Observations of the Brown Dwarf HD 19467 B

Alexandra Greenbaum (Caltech/IPAC)

2:30 to 2:40 pm PT, Room 615

HD 19467 B, a previously imaged brown dwarf with a known radial velocity trend, was observed with JWST's NIRCam at six wavelengths spanning 2.5–4.6 µm with the Long Wavelength Bar coronagraph without a reference star. We present an updated analysis of the properties of the HD 19467 system, including NIRCam photometry in six filters, new radial velocities from Keck/HIRES, and photometric data from TESS to constrain the properties of the host star. We apply the new relative astrometry and radial velocity measurements to an updated orbital analysis. We also do a preliminary comparison of the new photometry with atmospheric and evolutionary models. This work notably demonstrates post-processing using synthetic PSFs developed from contemporaneous maps of the telescope's optical configuration, identifying a potential, more efficient observational strategy for some high contrast observations with JWST.

Thursday, January 12

Sharing Wisdom on Effective Programs in Broader Impact Efforts (NSF Special Session/Splinter)

Luisa Rebull (Caltech/IPAC)

12:45 to 3:30 pm PT, Room 201

Dr. Luisa Rebull, Director of the NASA/IPAC Teacher Archive Research Program (NITARP) will discuss "In-depth Student and Teacher Exploration of Observations from National Facilities.

The Nation Science Foundation believes Broader Impact Efforts to share research with the community is important. The Astronomy Division intends/hopes this splinter session provides an opportunity to share experiences in public outreach with other researchers. We plan this session to have a few have a few opening remarks from members of the community and education and outreach experts at National Facilities followed by a discussion on

• Best practices.
• Areas where programs can be readily expanded
• Needs of Astronomers working to share their research with diverse communities.

A goal of this splinter session is to enable participants to advertise their outreach projects that might most effectively be shared with other researchers. Recipients of NSF awards are particularly encouraged to attend, especially if they feel their outreach efforts are both effective and extendable.

We also welcome those with cautions on how outreach and educations might be enhanced and improved.

449.02 Deblending Galaxies with Generative Adversarial Networks

Shoubaneh Hemmati (Caltech/IPAC)

2:10 to 2:20 pm PT

Deep generative models including generative adversarial networks (GANs) are powerful unsupervised tools in learning the distributions of data sets. Building a simple GAN architecture in PyTorch and training on the CANDELS data set, we generate galaxy images with the Hubble Space Telescope resolution starting from a noise vector. We proceed by modifying the GAN architecture to improve the Subaru Hyper Suprime-Cam ground-based images by increasing their resolution to the HST resolution. We use the super resolution GAN on a large sample of blended galaxies which we create using CANDELS cutouts. In our simulated blend sample, ~20% would unrecognizably be blended even in the HST resolution cutouts. In the HSC-like cutouts this fraction rises to ~ 90%. With our modified GAN we can lower this value to ~50%. We quantify the blending fraction in the high, low and GAN resolutions over the whole manifold of angular separation, flux ratios, sizes and redshift difference between the two blended objects. The two peaks found by the GAN deblender result in ten times improvement in the photometry measurement of the blended objects. Modifying the architecture of the GAN, we also train a Multi-wavelength GAN with seven band optical+NIR HST cutouts. This multi-wavelength GAN improves the fraction of detected blends by another ~10% compared to the single-band GAN. This is most beneficial to the current and future precision cosmology experiments (e.g., LSST, SPHEREx, Euclid, Roman), specifically those relying on weak gravitational lensing, where blending is a major source of systematic error.

448.08 Zooming in on the Shocked and Turbulent Intergalactic Medium in Stephan's Quintet with JWST and ALMA

Phil Appleton (Caltech/IPAC)

3:20 to 3:30 pm PT

We present some of the first sub-arcsecond resolution JWST and ALMA observations of the molecular and ionized gas in the highly turbulent intergalactic medium in Stephan's Quintet. We zoom-in on regions believed to contain highly shocked gas along the two molecular hydrogen filaments previously discovered and mapped with the Spitzer Space Telescope, Chandra and the VLA, and one region that may be forming a dwarf galaxy at the extreme edge of the main shocked region. Using a combination of data from JWST's NIRCam and MIRI detectors, and ALMA CO (2-1) data, we uncover amazing structures in warm and cold molecular gas, and in ionized hydrogen. We investigate the peculiar , and not yet understood relationship between gas carried into the group by the intruder galaxy NGC 7318b at 800 km/s and gas lying in the main group. We explore how kinetic energy is dissipated when the intruder collides with the group, seeing for the first time the complexity of gas flowing in the interface of two multi-phase media colliding a high mach number, and its effect on the formation of stars. The observations challenge our understanding of how molecular structures can survive high-speed collisions.

Posters

Monday, Jan. 9

106.08 A More Complete List of YSO Candidates in AFGL 490 (iPoster)

Rita Ciambra (Peoples Academy High School—NITARP Participant); Co-authors: M. Kuhnle,  D. Friedlander-Holm, C. Brady,  L. Eshaghpour-Silberman,  M. Herrera,  T. Swanson,  K. Gustavson, E. Tabak, M. Swigert, E. Van Winkle, J. Johnson, L. Rebull; Advisor: Luisa Rebull (Caltech/IPAC)

9 to 10 am PT

AFGL 490 is an embedded cluster of low-mass stars around the high-mass (8-10 M_sun) star AFGL 490 (Straižys & Laugalys 2008), located within the plane of the Galaxy in the Cam OB1 association. Within this cluster are many young stellar objects (YSOs) emerging from the dust cloud surrounding AFGL 490. A complete list of YSO candidates is useful to compare the cluster's properties to other, older clusters, since much about cluster development is still unknown. This project worked towards developing just such a list. This built upon work done by Gutermuth et al. (2009) and Masiunas et al. (2012), who studied this cluster with Spitzer/IRAC (Infrared Array Camera) and MIPS (Multi-band Imaging Photometer for Spitzer), as well as information from the YSOVAR (YSO VARiability) project (Rebull et al. 2014) which monitored this region with Spitzer/IRAC. The initial YSO list also included cluster members identified by Winston (2020) using the Wide-Field Infrared Survey Explorer (WISE), Spitzer/IRAC, and the Two Micron All Sky Survey (2MASS). Objects identified as having H-alpha excess (Barentsen 2014) were also investigated.

We collected the literature-identified YSOs, and looked for new potential candidates using H-alpha and IR variability. We then combined data from several optical databases (Panoramic Survey Telescope and Rapid Response System [PanSTARRS], INT Photometric H-Alpha Survey [IPHAS], and Gaia) and IR (Spitzer/IRAC & MIPS, WISE, Herschel/Photodetector Array Camera and Spectrometer [PACS], Akari, Midcourse Space Experiment [MSX]) data sets. Starting from 517 YSO candidates from the literature or identified anew, each source was analyzed using image inspection, spectral energy distributions, color-color/color-magnitude diagrams and light curves to identify which targets were strong YSO candidates; we narrowed down our final list to 501 candidate YSOs.

This research was made possible through the NASA/IPAC Teacher Archive Research Program (NITARP) and was funded by the NASA Astrophysics Data Program.

164.06 Search for wide-orbit companions around late-M stars from Subaru/IRD Strategic Program (iPoster)

T. Uyama (Caltech/IPAC)

5:30 to 6:30 pm PT

Subaru/IRD is a high-dispersion near-infrared spectrograph enabling search for exoplanets around late-M stars by radial velocity. We have implemented the strategic observational program (Subaru/IRD-SSP) to mainly search for terrestrial planets around late-M stars. Besides the signal of close-in planets we have seen potential RV trends that suggest outer companions, which is not prioritized in the SSP campaign. However, the demographics of companions around late-M stars is not well established. Here we have started Keck/NIRC2 follow-up direct imaging search for companions around the IRD-SSP targets. We took into account `irregularity' of the RV measurements from our Subaru/IRD observations and Gaia information (`RUWE') to infer the potential companions, and prioritized those with such implications. We present the latest Keck imaging results with resolved companion candidates in this meeting.

168.01 NGSS Science and Engineering Practices in Secondary Education through Real Astronomical Research (iPoster)

Janine Bonham (Oley Valley High School—NITARP Participant); Co-authors: V. Gorjian, J. Benter, A. Karsten, O. Kuper,  N. Deyton,  B. Gulden, E. Kopicki, C. Miller, Z. Potter, C. Robertson, Z. Thomas, W. Ulsh, J. Zimmerman; Advisor: Varoujan Gorjian (JPL/Caltech)

5:30 to 6:30 pm PT, Exhibit Hall 4AB

The NASA/IPAC Teacher Archive Research Program (NITARP) provides middle and high school science teachers with a unique opportunity to engage in high-level primary research with an astronomer. In this particular study, four teachers, side-by-side with nine of their selected students, participated in an archival search for the presence of infrared excess around M-class dwarf stars to determine the possible presence of asteroidal and cometary debris, which may point to the presence of terrestrial exoplanets. Over the course of one year, students and teachers collaborated in both virtual and physical settings to learn about scientific concepts and how to use NASA's Infrared Science Archive (IRSA) and Spitzer Enhanced Imaging Products (SEIP) Catalog to access data and analyze results. Through this process of doing authentic science, teachers and their students utilized the Science and Engineering Practices of the Next Generation Science Standards (NGSS), which strive to move the real world methods of "doing science" into classrooms. One educational focus for this project was to incorporate the eight practices of science and engineering that are identified in the NGSS into student instruction, especially those of questioning, active student research, collaboration with peers, and communication of results. Students and teachers were surveyed to examine how their view of learning and teaching science changed after participating in authentic research practices. After completing the NITARP program, all students and teacher perceptions of science shifted. This research was made possible through the NASA/IPAC Teacher Archive Research Program (NITARP) and was funded by NASA Astrophysics Data Program.

168.02 Teacher Roles within NITARP; a 13-month Research Collaboration (iPoster)

Mary Swigert (Jupiter Community High School—NITARP Participant); Co-authors: K. Gustavson, R. Ciambra, D. Friedlander-Holm, E. Van Winkle, L. Rebull; Advisor: Luisa Rebull (Caltech/IPAC)

5:30 to 6:30 pm PT, Exhibit Hall 4AB

The 2022 NITARP team of Luisa Rebull, consisting of seven students and five teachers, examined the literature and data concerning low mass, young stellar objects near AFGL 490, a high mass star with surrounding dust in Cam OB-1.

The benefits for both students and teachers were extensive; including learning astrophysics, participating in real world science, analyzing data, and getting a glimpse into the world of professional astronomy. This poster will highlight the ways in which the teachers and their students brought this experience back to their communities.

This research was made possible through the NASA/IPAC Teacher Archive Research Program (NITARP) and was funded by the NASA Astrophysics Data Program.

Thursday, Jan. 12

405.01 New far-UV imaging (WFC3/F225W) on Hubble Frontier Fields: new catalogs and photometric redshifts (iPoster)

Anahita Alavi (Caltech/IPAC)

9 to 10 am PT, Exhibit Hall 4AB

The Hubble Frontier Fields (HFF) program observes 6 massive lensing galaxy clusters in optical and near-IR using the ACS and WFC3 cameras on the Hubble Space Telescope (HST). Our program extends the HFF observations to far-ultraviolet by imaging in the F225W band using the WFC3/UVIS channel on HST. Covering far-UV wavelengths opens up an immense range of science for both the lensed background galaxies and cluster members. In particular, it enables us to set significantly stronger constraints on the photometric redshift of star-forming galaxies down to z~1 through the identification of the Lyman-break. Accurate photometric redshifts are essential for constraining strong gravitational lensing models, and thus accurate estimates of the luminosity, deriving average properties for galaxies vs. cosmic time and constraining the UV luminosity function (LF).

In this work, we present new photometric catalogs and photometric redshifts for HFFs including these new UV observations. Since UV sources are usually more compact and have a lower signal to noise, a routine aperture-matched PSF-matched photometry would further degrade the UV signal to noise ratio. Therefore we measure UV photometry in the original high-resolution UV data. Specifically, we perform source detection on the F435W mosaics to obtain isophotes that better match the galaxy morphology in the bluer/UV wavelengths. We utilize photometry over all available HST filters along with K-band and IRAC ch.1,2 for the photometric redshift estimation. We use a collection of spectroscopic redshifts available from a multitude of literature studies over the HFF fields to calibrate for photometric zeropoint offsets and to validate the performance of the measured photometric redshifts.

474.02 Can Gaia Help Us Find Dippers? (iPoster)

Luisa Rebull(Caltech/IPAC)

1 to 2 pm PT, Exhibit Hall 4AB

Dipper stars have light curves with a "continuum" bright state punctuated by dips, or fading events. They are interpreted as occultations of the star by circumstellar material based on wavelength-dependence of the dip depths and in some cases infrared excess, with hundreds now found in K2 and TESS data of various star-forming regions. In the IC 417 star-forming region, Rebull et al. (2023), notably find that Gaia DR3, which identifies eclipsing binaries (EBs) based on its time series photometry, has in every single case confused the EB phenomenon with the dipper phenomenon. Zwicky Transient Facility (ZTF) lightcurves and Spitzer mid-infrared photometry confirm lightcurve morphology and infrared excess in these sources. Broadening the investigation, we have cross-matched the entire Gaia EB catalog with mid-infrared photometry in the Spitzer Enhanced Imaging Products (SEIP) source catalog, and lightcurves in the Transiting Exoplanet Survey Satellite (TESS) high level science products (HLSP). Among this sample, about 65% of the Gaia-identified EBs are indeed EBs in the TESS data, and about 25% are periodic rotators. Just 2% (12 sources) are dippers, though this fraction increases if infrared excess is also required.

474.03 Survey of the Spitzer Enhanced Imaging Products (SEIP) Catalog for Potential Debris Disks Around Main Sequence M Class Stars (iPoster)

Jeff Benter (Tri-Valley High School—NITARP Participant); Co-authors: J. Bonham, A. Karsten, O. Kuper, N. Deyton, B. Gulden, E. Kopicki, C. Miller, Z. Potter, C. Robertson, Z. Thomas, W. Ulsh, J. Zimmerman; Advisor: Varoujan Gorjian (JPL/Caltech)

1 to 2 pm PT, Exhibit Hall 4AB

M class dwarf stars are the most common type of star but, due to their low luminosities and similar spectral characteristics to M class red giants, relatively few exoplanets have currently been identified orbiting them. An approach to establishing the possible existence of terrestrial exoplanets in M dwarf systems is the detection, using infrared excess, of a debris disk orbiting a mature star. A survey of the Spitzer Enhanced Imaging Products (SEIP) catalog, a collection of nearly 42 million point sources obtained by the Spitzer Space Telescope during its 5+ year cryogenic mission, was a starting point to search for infrared evidence of debris disks. In this study, we examined isolated sources in the SEIP with a signal-to-noise ratio (SNR) greater than 5 in four IR wavelength channels (3.6, 4.5, 8, and 24 microns) to search for sources with infrared excess in order to obtain a large and reliable set of candidates. Using Gaia distances, we refined the search to 553 main sequence M stars in the SEIP by excluding M class red giants. Visual inspection of these sources to ensure a valid point source reduced these eligible candidates by a third by eliminating images with contamination due to nearby companions, cosmetic defects, or other infrared dilution. Final selection of dwarf M stars was made by excluding known young stellar objects and sources near star-forming regions, which may show an infrared excess due to a remnant star forming disk. This final selection creates a catalog of approximately 70 mature red dwarf stars with debris disks for potential followup searches for the presence of rocky exoplanets. This research was made possible through the NASA/IPAC Teacher Archive Research Program (NITARP) and was funded by NASA Astrophysics Data Program.

467.03 Implications of star-formation histories on the inferred stellar physical properties of galaxies with UVCANDELS (iPoster)

Vihang Mehta (Caltech/IPAC)

1 to 2 pm PT, Exhibit Hall 4AB

The Ultraviolet Imaging of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey Fields (UVCANDELS) program provides UV imaging for four CANDELS fields (GOODS-N, GOODS-S, COSMOS and EGS). UVCANDELS acquired 164 orbits of imaging covering a total of ~430 sq. arcminutes over the four fields with WFC3/F275W and ACS/F435W imaging reaching a 5-sigma point-source depth of 27 AB and 28 AB respectively. This UV imaging provides key constraints on the recent star-formation activity in galaxies at the cosmic high-noon. We estimate stellar population properties from SED fitting via two separate approaches to describing star-formation histories -- a traditional method using CIGALE (Boquien+19) that relies on fixed star-formation histories and a modern approach using Dense Basis (Iyer+19) that allows for flexible star-formation histories. We present a comparison of the best-fit estimates from these complementary approaches and discuss the systematic biases introduced in key physical properties, such as galaxy stellar masses, due to the assumptions about galaxy star-formation histories.

Hyperwall Presentations

All Hyperwall events are held in the Exhibit Hall

Monday, January 9

Building the Nancy Grace Roman Space Telescope

Dominic Benford

7:05 to 7:20 am PT

Completing the Galactic Census of Exoplanets with Roman

Scott Gaudi

5:30 to 5:45 pm PT

Tuesday, January 10

Nancy Grace Roman Space Telescope Coronagraph Instrument

Alexandra Greenbaum (Caltech/IPAC)

9:20 to 9:35 am PT

Future Science with NASA's Nancy Grace Roman Space Telescope

Karoline Gilbert

2:15 to 2:30 pm PT

The Dynamic Sky with NASA's Roman Space Telescope

Ori Fox

2:30 to 2:45 pm PT

The NASA Exoplanet Archive Breaks The Fourth Wall

Jessie Christiansen (Caltech/IPAC-NExScI)

6 to 6:15 pm PT

Wednesday, January 11

Extragalactic magnetism with SOFIA (SALSA Legacy Program)

Enrique Lopez-Rodriguez

9:20 to 9:35 am PT

NED and Open Science

Joe Mazzarella (Caltech/IPAC-NED)

2:15 to 2:30 pm PT

US Archival Science with Euclid

Shoubaneh Hemmati (Caltech/IPAC)

5:45 to 6 pm PT

NASA's Astrophoto Challenge: Engage the Public to Create Their Own Astronomical Images with NASA Data

Rutuparna Das

6:15 to 6:30 pm PT

Thursday, January 12

Roman Space Telescope's Wide Field Instrument

Ami Choi

9:05 to 9:20 am PT

NASA's Astrophoto Challenge: Engage the Public to Create Their Own Astronomical Images with NASA Data

Rutuparna Das

1:45 to 2 pm PT