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1. Targeted HI Line Observations of Low Mass Galaxies in the Pisces-Perseus Supercluster: Results for the Declination Strip 30° < Dec < 32°

   Kumagai, Samuel F. ( January 2019 , American Astronomical Society, AAS Meeting)

   The Arecibo Pisces-Perseus Supercluster Survey (APPSS) is an observing project undertaken by the Undergraduate ALFALFA Team that aims to detect HI in galaxies in the Pisces-Perseus neighborhood and analyze the dynamics and the properties of the galaxies. The galaxies targeted in APPSS are suspected from their optical properties (color, morphology, surface brightness) to lie in the Pisces-Perseus Supercluster (PPS) but are below the detection threshold of the ALFALFA blind HI survey. Here we present results for galaxies targeted in a strip across the PPS region in declination from 30o to 32o. This region is along the main filament of the supercluster and includes objects such as the Pisces Cluster. The data was recorded by the L-Band Wide receiver of the Arecibo Observatory. Data reduction was done using routines derived for the APPSS in IDL. After baselining the spectra and sifting out radio interference, we fit either a gaussian or two-horned profile to their 21-centimeter line to measure the HI line flux density, velocity, and velocity width. From these parameters we calculate distances, hydrogen gas mass, and rotational velocities. As expected, the galaxies analyzed in this slice of declination have consistently lower mass than the ALFALFA detections thus extending the sampling of galaxies within the PPS. The combined ALFALFA and APPSS HI line detections will be used for future applications of the Baryonic Tully-Fisher Relation in this region. This research has been supported by NSF grant NSF/AST-1714828 to M.P. Haynes and by the Brinson Foundation for the Arecibo Pisces-Perseus Supercluster Survey (APPSS). 

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2. The Arecibo Pisces-Perseus Supercluster Survey: Characteristics of the APPSS Galaxy Population

   Montalvo, B. ; Haynes, M. P. ; Team, Undergraduate Alfalfa ( January 2020 , American Astronomical Society meeting)

   The Arecibo Pisces-Perseus Supercluster Survey(APPSS) aims to measure the infall and mass density along the PPS filament using red-shift independent distances obtained from the Baryonic Tully-Fisher Relation (BTFR). We will combine photometric data from the Sloan Digital Sky Survey with HI line spectroscopy obtained with the Arecibo telescope to derive BTFR distances and peculiar velocities over the PPS volume and its immediate foreground and background. To supplement the ALFALFA detections in the PPS volume, we have conducted new HI line observations with the Arecibo L-band Wide receiver system of blue, low surface brightness galaxies identified by their photometric properties in the Sloan Digital Sky Survey (SDSS). These targets are predicted to lie in the PPS volume but with HI masses of 8.0 < log HI mass < 9.0, putting them below the ALFALFA detection limit at that distance. We compare a preliminary sample of 634 galaxies detected as part from the APPSS survey with the main ALFALFA survey and other public catalogs of local galaxies, confirming that the new APPSS HI line detections are rotation-dominated, HI bearing galaxies with low stellar mass. Nearly all are star-forming, bluer, and of lower surface brightness, extinction and metallicity than optically selected samples. Preliminary BTFRs were calculated for both APPSS and ALFALFA galaxies and compared with BTFRs of simulated galaxies similar to those found in APPSS and ALFALFA using simulations such as IllustrisTNG (see poster by J. Borden). This work has been supported by NSF/AST-1714828 and the Brinson Foundation. 

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3. The Arecibo Pisces-Perseus Survey: Goals, data reduction, and initial results from declination strips 23 and 33

   Luna, Omar ; Craig, David W. ; Jones, Michael ; Haynes, Martha P. ; Koopmann, Rebecca ( January 2019 , American Astronomical Society, AAS Meeting #233, id.356.07)

   The Arecibo Pisces-Perseus Supercluster Survey (APPSS) attempts to detect the infall of galaxies onto the Pisces-Perseus Supercluster (PPS). The ALFALFA survey has greatly augmented the known redshifts across the region. APPSS sources will complement the ALFALFA sources, with the goal of building a large enough sample to make a high confidence measurement of infall and backflow onto the PSS filament via peculiar velocity estimates from the Tully-Fisher (TFR) and Baryonic Tully-Fisher (BTFR) relations. APPSS galaxies are selected using photometric data from the Sloan Digital Sky Survey (SDSS), aimed to detect low-mass, nearby gas-rich objects below the ALFALFA detection limit. The L-band wide receiver at Arecibo Observatory in Puerto Rico is used to obtain a five-minute ON-OFF measurement for each galaxy. Since the candidate galaxy redshifts are unknown, the receiver and spectrograph system are used in a search mode that spans the expected frequencies of HI emission from PPS galaxies. We will describe the goals, target selection, and data reduction process for the survey. Our collaboration has divided the PPS into two-degree wide declination strips for data reduction; we report preliminary results for strips 23 and 33. We have made the initial data reduction on more than 200 targets, and determined the systemic velocity, line width, integrated flux density, and HI mass for each candidate detection. We will compare results on our two declination strips, and point out interesting detections found along the way as examples of the data reduction process. This work has been supported by NSF grants AST-1211005 and AST-1637339. Publication: American Astronomical Society, AAS Meeting #233, id.356.07 Pub Date: January 2019 Bibcode: 2019AAS...23335607L 

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4. The Arecibo Pisces-Perseus Survey: Goals, data reduction, and initial results from declination strips 23 and 33

   Luna, Omar ; Craig, David W. ; Jones, Michael ; Haynes, Martha P. ; Koopmann, Rebecca ( January 2019 , American Astronomical Society, AAS Meeting)

   The Arecibo Pisces-Perseus Supercluster Survey (APPSS) attempts to detect the infall of galaxies onto the Pisces-Perseus Supercluster (PPS). The ALFALFA survey has greatly augmented the known redshifts across the region. APPSS sources will complement the ALFALFA sources, with the goal of building a large enough sample to make a high confidence measurement of infall and backflow onto the PSS filament via peculiar velocity estimates from the Tully-Fisher (TFR) and Baryonic Tully-Fisher (BTFR) relations. APPSS galaxies are selected using photometric data from the Sloan Digital Sky Survey (SDSS), aimed to detect low-mass, nearby gas-rich objects below the ALFALFA detection limit. The L-band wide receiver at Arecibo Observatory in Puerto Rico is used to obtain a five-minute ON-OFF measurement for each galaxy. Since the candidate galaxy redshifts are unknown, the receiver and spectrograph system are used in a search mode that spans the expected frequencies of HI emission from PPS galaxies. We will describe the goals, target selection, and data reduction process for the survey. Our collaboration has divided the PPS into two-degree wide declination strips for data reduction; we report preliminary results for strips 23 and 33. We have made the initial data reduction on more than 200 targets, and determined the systemic velocity, line width, integrated flux density, and HI mass for each candidate detection. We will compare results on our two declination strips, and point out interesting detections found along the way as examples of the data reduction process. This work has been supported by NSF grants AST-1211005 and AST-1637339. 

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5. A Local Baryonic Tully-Fisher Relation from IllustrisTNG

   Borden, J. T. ; Jones, M. G. ; Haynes, M. P. ( January 2020 , American Astronomical Society meeting)

   The Pisces-Perseus Supercluster (PPS) offers a convenient, accessible environment for the study of large scale structure in the local universe. The Arecibo Pisces-Perseus Supercluster Survey (APPSS) seeks to observe the infall of galaxies toward the main filament of the PPS which is nearly perpendicular to our line of sight. Tracing such infall reveals valuable information about the gravitational field - and thus mass distribution - of the PPS. However, obtaining accurate measurements of such deviation from smooth Hubble flow requires redshift-independent distance measurements. The baryonic Tully-Fisher relation (BTFR) offers an appealing solution in the distance regime of the PPS, but while the high-mass end of this relation boasts a tight correlation, the low-mass end - where the APPSS sample lies - shows considerably more scatter. We use the magnetohydrodynamical simulations of IllustrisTNG to examine a template BTFR in an attempt to better understand the error budget of, and identify systematic scatter within, the BTFR as it corresponds to the APPSS sample of galaxies. We find the low mass scatter of the simulated BTFR to be populated predominantly by highly gas dominated, low surface brightness galaxies with colors less blue than typical. This unusually quiescent subset of galaxies appears to share systematically inefficient star formation, with very high gas depletion timescales that deviate rapidly from an otherwise gradual trend apparent throughout the rest of the galaxy population. This subset of inefficiently star forming galaxies tends to decrease the slope of the BTFR at low masses, an effect that lies in contrast to the steepening of the BTFR generally expected in this mass regime. Further work is needed to determine if this collection of galaxies is physically motivated or is instead a finite resolution effect of the simulation. This work is supported by NSF/AST-1714828 to MPH. 

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