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We present the results from the HST WFC3 and ACS data on an archetypal galaxy undergoing ram pressure stripping (RPS), ESO 137-001, in the nearby cluster Abell 3627. ESO 137-001 is known to host a prominent stripped tail detected in many bands from X-rays, H α to CO. The HST data reveal significant features indicative of RPS such as asymmetric dust distribution and surface brightness as well as many blue young star complexes in the tail. We study the correlation between the blue young star complexes from HST, H ii regions from H α (MUSE), and dense molecular clouds from CO (ALMA). The correlation between the HST blue star clusters and the H ii regions is very good, while their correlation with the dense CO clumps are typically not good, presumably due in part to evolutionary effects. In comparison to the starburst99 + cloudy model, many blue regions are found to be young (<10 Myr) and the total star formation (SF) rate in the tail is 0.3–0.6 M⊙ yr−1 for sources measured with ages less than 100 Myr, about 40 per cent of the SF rate in the galaxy. We trace SF over at least 100 Myr and give a full picture of the recent SF history in the tail. We also demonstrate the importance of including nebular emissions and a nebular to stellar extinction correction factor when comparing the model to the broad-band data. Our work on ESO 137-001 demonstrates the importance of HST data for constraining the SF history in stripped tails.

 

The MMTO Adaptive optics exoPlanet characterization System (MAPS) is an ongoing upgrade to the 6.5-meter MMT Observatory on Mount Hopkins in Arizona. MAPS includes an upgraded adaptive secondary mirror (ASM), upgrades to the ARIES spectrograph, and a new AO system containing both an optical and near-infrared (NIR; 0.9-1.8 μm) pyramid wavefront sensor (PyWFS). The NIR PyWFS will utilize an IR-optimized double pyramid coupled with a SAPHIRA detector: a low-read noise electron Avalanche Photodiode (eAPD) array. This NIR PyWFS will improve MAPS's sky coverage by an order of magnitude by allowing redder guide stars (e.g. K & M-dwarfs or highly obscured stars in the Galactic plane) to be used. To date, the custom designed cryogenic SAPHIRA camera has been fully characterized and can reach sub-electron read noise at high avalanche gain. In order to test the performance of the camera in a closed-loop environment prior to delivery to the observatory, an AO testbed was designed and constructed. In addition to testing the SAPHIRA's performance, the testbed will be used to test and further develop the proposed on-sky calibration procedure for MMTO's ASM. We will report on the anticipated performance improvements from our NIR PyWFS, the SAPHIRA's closed-loop performance on our testbed, and the status of our ASM calibration procedure. 

The MMT Adaptive optics exoPlanet characterization System (MAPS) is an exoplanet characterization program that encompasses instrument development, observational science, and education. The instrument we are developing for the 6.5m MMT observatory is multi-faceted, including a refurbished 336-actuator adaptive secondary mirror (ASM); two pyramid wavefront sensors (PyWFS's); a 1-kHz adaptive optics (AO) control loop; a high-resolution and long-wavelength upgrade to the Arizona infraRed Imager and Echelle Spectrograph (ARIES); and a new-AO-optimized upgrade to the MMT-sensitive polarimeter (MMT-Pol). With the completed MAPS instrument, we will execute a 60-night science program to characterize the atmospheric composition and dynamics of ~50-100 planets around other stars. The project is approaching first light, anticipated for Summer/Fall of 2022. With the electrical and optical tests complete and passing the review milestone for the ASM's development, it is currently being tuned. The PyWFS's are being built and integrated in their respective labs: the visible-light PyWFS at the University of Arizona (UA), and the infrared PyWFS at the University of Toronto (UT). The top-level AO control software is being developed at UA, with an on-sky calibration algorithm being developed at UT. ARIES development continues at UA, and MMT-Pol development is at the University of Minnesota. The science and education programs are in planning and preparation. We will present the design and development of the entire MAPS instrument and project, including an overview of lab results and next steps. 

MAPS, MMT Adaptive optics exoPlanet characterization System, is the upgrade of the adaptive optics system for 6.5-m MMT. It is an NSF MSIP-funded project that includes developing an adaptive-secondary mirror, visible and near-infrared pyramid wavefront sensors, and the upgrade of Arizona infrared imager and echelle spectrograph (ARIES) and MMT High Precision Imaging Polarimeter (MMTPol) science cameras. This paper will present the design and development of the visible pyramid wavefront sensor, VPWFS. It consists of an acquisition camera, a fast-steering tip-tilt modulation mirror, a pyramid, a pupil imaging triplet lens, and a low noise and high-speed frame rate based CCID75 camera. We will report on hardware and software, present the laboratory characterization results of individual subsystems, and outline the on-sky commissioning plan. 

ABSTRACT Previous studies have revealed a population of galaxies in galaxy clusters with ram pressure stripped (RPS) tails of gas and embedded young stars. We observed 1.4 GHz continuum and H i emission with the Very Large Array in its B-configuration in two fields of the Coma cluster to study the radio properties of RPS galaxies. The best continuum sensitivities in the two fields are 6 and 8 µJy per 4 arcsec beam, respectively, which are 4 and 3 times deeper than those previously published. Radio continuum tails are found in 10 (8 are new) out of 20 RPS galaxies, unambiguously revealing the presence of relativistic electrons and magnetic fields in the stripped tails. Our results also hint that the tail has a steeper spectrum than the galaxy. The 1.4 GHz continuum in the tails is enhanced relative to their H α emission by a factor of ∼7 compared to the main bodies of the RPS galaxies. The 1.4 GHz continuum of the RPS galaxies is also enhanced relative to their infrared emission by a factor of ∼2 compared to star-forming galaxies. The enhancement is likely related to ram pressure and turbulence in the tail. We furthermore present H i detections in three RPS galaxies and upper limits for the other RPS galaxies. The cold gas in D100’s stripped tail is dominated by molecular gas, which is likely a consequence of the high ambient pressure. No evidence of radio emission associated with ultra-diffuse galaxies is found in our data. 

We are upgrading and refurbishing the first-generation adaptive-secondary mirror (ASM)-based AO system on the 6.5-m MMT in Arizona, in an NSF MSIP-funded program that will create a unique facility specialized for exoplanet characterization. This update includes a third-generation ASM with embedded electronics for low power consumption, two pyramid wavefront sensors (optical and near-IR), and an upgraded ARIES science camera for high-resolution spectroscopy (HRS) from 1-5 μm and MMT-POL science camera for sensitive polarization mapping. Digital electronics have been incorporated into each of the 336 actuators, simplifying hub-level electronics and reducing the total power to 300 W, down from 1800 W in the legacy system — reducing cooling requirements from active coolant to passive ambient cooling. An improved internal control law allows for electronic damping and a faster response. The dual pyramid wavefront sensors allow for a choice between optical or IR wavefront sensing depending on guide star magnitude, color, and extinction. The HRS upgrade to ARIES enables crosscorrelation of molecular templates to extract atmospheric parameters of exoplanets. The combination of these upgrades creates a workhorse instrument for exoplanet characterization via AO and HRS to separate planets from their host stars, with broad wavelength coverage and polarization to probe a range of molecular species in exoplanet atmospheres.