The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is currently acquiring integral-field spectroscopy for the largest sample of galaxies to date. By 2020, the MaNGA Survey-which ...is one of three core programs in the fourth-generation Sloan Digital Sky Survey (SDSS-IV)-will have observed a statistically representative sample of 104 galaxies in the local universe (z 0.15). In addition to a robust data-reduction pipeline (DRP), MaNGA has developed a data-analysis pipeline (DAP) that provides higher-level data products. To accompany the first public release of its code base and data products, we provide an overview of the MaNGA DAP, including its software design, workflow, measurement procedures and algorithms, performance, and output data model. In conjunction with our companion paper (Belfiore et al.), we also assess the DAP output provided for 4718 observations of 4648 unique galaxies in the recent SDSS Data Release 15 (DR15). These analysis products focus on measurements that are close to the data and require minimal model-based assumptions. Namely, we provide stellar kinematics (velocity and velocity dispersion), emission-line properties (kinematics, fluxes, and equivalent widths), and spectral indices (e.g., D4000 and the Lick indices). We find that the DAP provides robust measurements and errors for the vast majority (>99%) of analyzed spectra. We summarize assessments of the precision and accuracy of our measurements as a function of signal-to-noise. We also provide specific guidance to users regarding the limitations of the data. The MaNGA DAP software is publicly available and we encourage community involvement in its development.
We used integral field spectroscopy from CALIFA DR3 and multiwavelength publicly available data to investigate the star formation histories of galaxies in the Seyfert's Sextet (SS; HCG 79). The ...galaxies H79a, H79b, H79c, and H79f have low star formation rates despite showing strong signs of interaction. By exploring their individual specific star formation histories, we identified three earlier episodes of strong star formation common to these four galaxies. We use the last two episodes as markers of the epochs when the galaxies were crossing. We suggest that after the first turnaround, initially gas-rich galaxies crossed for the first time, consuming most of their gas. Hence, after the second turnaround most mergers from second crossings would be mixed or dry. The exception would be gas-rich galaxies intruding for the first time. Therefore, we suggest that SS galaxies have survived one crossing during a Hubble time. Strong Balmer absorption lines and the presence of counter-rotating disks provide independent bounds to the second and first crossing, respectively. This scenario provides a plausible way out of the short crossing time paradox.
Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) is acquiring integral-field spectroscopy for the largest sample of galaxies to date. By 2020, the MaNGA Survey --- one of three core ...programs in the fourth-generation Sloan Digital Sky Survey (SDSS-IV) --- will have observed a statistically representative sample of 10\(^4\) galaxies in the local Universe (\(z\lesssim0.15\)). In addition to a robust data-reduction pipeline (DRP), MaNGA has developed a data-analysis pipeline (DAP) that provides higher-level data products. To accompany the first public release of its code base and data products, we provide an overview of the MaNGA DAP, including its software design, workflow, measurement procedures and algorithms, performance, and output data model. In conjunction with our companion paper Belfiore et al., we also assess the DAP output provided for 4718 observations of 4648 unique galaxies in the recent SDSS Data Release 15 (DR15). These analysis products focus on measurements that are close to the data and require minimal model-based assumptions. Namely, we provide stellar kinematics (velocity and velocity dispersion), emission-line properties (kinematics, fluxes, and equivalent widths), and spectral indices (e.g., D4000 and the Lick indices). We find that the DAP provides robust measurements and errors for the vast majority (\(>\)99%) of analyzed spectra. We summarize assessments of the precision and accuracy of our measurements as a function of signal-to-noise, and provide specific guidance to users regarding the limitations of the data. The MaNGA DAP software is publicly available and we encourage community involvement in its development.
We used integral field spectroscopy from CALIFA DR3 and multiwavelength publicly-available data to investigate the star-formation histories of galaxies in the Seyfert's Sextet (SS, HCG 79). The ...galaxies H79a, H79b, H79c, and H79f have low star-formation rates despite showing strong signs of interaction. By exploring their individual specific star formation histories (sSFH), we identified three earlier episodes of strong star formation common to these four galaxies. We use the last two episodes as markers of the epochs when the galaxies were crossing. We suggest that after the first turn-around, initially gas-rich galaxies crossed for the first time, consuming most of their gas. Hence after the second turn-around most mergers from second crossings would be mixed or dry. The exception would be gas-rich galaxies intruding for the first time. Therefore, we suggest that SS galaxies have survived one crossing during a Hubble time. Strong Balmer absorption lines and the presence of counter-rotating disks provide independent bounds to the second and first crossing, respectively. This scenario provides a plausible way out of the short crossing time paradox.
The gravitational magnification provided by massive galaxy clusters makes it possible to probe the physical conditions in distant galaxies that are of lower luminosity than those in blank fields and ...likely more representative of the bulk of the high-redshift galaxy population. We aim to constrain the basic properties of molecular gas in a strongly magnified submm galaxy located behind the massive Bullet Cluster. This galaxy (SMM J0658) is split into three images, with a total magnification factor of almost 100. We used the Australia Telescope Compact Array (ATCA) to search for {12}CO(1--0) and {12}CO(3--2) line emission from SMM J0658. We also used the SABOCA bolometer camera on the Atacama Pathfinder EXperiment (APEX) telescope to measure the continuum emission at 350 micron. CO(1--0) and CO(3--2) are detected at 6.8 sigma and 7.5 sigma significance when the spectra toward the two brightest images of the galaxy are combined. From the CO(1-0) luminosity we derive a mass of cold molecular gas of (1.8 \pm 0.3) * 10^9 Msun, using the CO to H_2 conversion factor commonly used for luminous infrared galaxies. This is 45 \pm 25 % of the stellar mass. From the width of the CO lines we derive a dynamical mass within the CO-emitting region L of (1.3 \pm 0.4) * 10^10 (L/1 kpc) Msun. We refine the redshift determination of SMM J0658 to z=2.7793 \pm 0.0003. Continuum emission at 350 micron from SMM J0658 was detected with SABOCA at a signal-to-noise ratio of 3.6. We study the spectral energy distribution of SMM J0658 and derive a dust temperature of 33\pm 5 K and a dust mass of 1.1*10^7 Msun. SMM J0658 is one of the least massive submm galaxies discovered so far. As a likely representative of the bulk of the submm galaxy population, it is a prime target for future observations.
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