VizieR Online Data Catalog: Most luminous SPIRITS IR transients follow-up obs. (Jencson+, 2019)

For transients that were inaccessible to ground-based observing at the time of discovery with Spitzer, we attempted to trigger Target of Opportunity (ToO) observations with the Neil Gehrels Swift Observatory UV/Optical Telescope (Swift/UVOT) to detect an optical counterpart or obtain limits on the contemporaneous optical flux. For SPIRITS 16tn we triggered a 2000s observation on 2016 August 29.1 split between the U, B, and V bands. For SPIRITS 17lb we obtained a 1200s integration in the V band on 2017 June 9.4. or SPIRITS 17pc we obtained a 2000s observation on 2017 November 9.1.

We also executed Hubble Space Telescope (HST) ToO observations of SPIRITS 16tn using the Wide Field Camera 3 (WFC3) in the UVIS channel with the F814W filter and the IR channel with the F110W and F160W filters as part of our program to follow up SPIRITS transients (GO-14258; PI: H. Bond) on 2016 September 25 as described in Jencson+ (2018ApJ...863...20J).

SPIRITS galaxies were regularly monitored from the ground in the optical and near-IR with several telescopes. For the SPIRITS transient host galaxies discussed here, sequences of optical g'r'i'-band images of IC 2163, M100, NGC 4461, NGC 3556, and NGC 4388 were obtained with the CCD camera on the fully automated Palomar 60-inch telescope (P60) throughout 2014-2018. Similarly for SPIRITS galaxies located in the southern hemisphere, namely, NGC 2997, IC 2163, and NGC 1365, sequences of optical gri-band images were obtained with the CCD camera on the 1m Swope Telescope at Las Campanas Observatory (LCO) throughout 2014-2015. Near-IR YJH-band images were also obtained throughout 2014-2015 with the RetroCam IR camera on the 2.5m du Pont Telescope at LCO. We also obtained and performed PSF photometry on the images of NGC5921 reported at CBAT for PSN J15220552+0503160 (SPIRITS 15ade), including unfiltered CCD images obtained by M. Aoki, G. Masi, and T. Noguchi, along with post-discovery images of this galaxy in the R band from the Hiroshima One-shot Wide-field Polarimeter (HOWpol) on the Kanata 1.5m telescope at Higashi-Hiroshima Observatory and in the r band with the Dark Energy Camera (DECam) on the Blanco 4m telescope at Cerro Tololo Inter-American Observatory (CTIO).

Post-discovery, ground-based follow-up imaging in the optical and near-IR was also obtained for several SPIRITS transients. Near-IR JHKs-band images were obtained with the Multi-object Spectrometer for Infra-red Exploration (MOSFIRE) on the 10m Keck I Telescope of the W. M. Keck Observatory on the summit of Maunakea, the Wide Field Infrared Camera (WIRC) on the 200-inch telescope at Palomar Observatory (P200), and the FourStar IR camera on the Magellan Baade Telescope at LCO. Additional near-IR imaging for SPIRITS 17lb was obtained with the FLAMINGOS-2 imaging spectrograph on the 8.1m Gemini S Telescope (PID GS-2017B-Q-15; PI J. Jencson). Optical imaging was obtained for SPIRITS 17pc using the DEep Imaging Multi-Object Spectrograph (DEIMOS) on the 10m Keck II Telescope. Additional near-IR imaging was obtained with the Wide Field Camera (WFCAM) on the United Kingdom Infrared Telescope (UKIRT) at Maunakea Observatories. Simultaneous optical/near-IR rizYJH were obtained with the Reionization and Transients InfraRed camera (RATIR) on the 1.5m Johnson Telescope at the Mexican Observatorio Astronomico Nacional on the Sierra San Pedro Martir in Baja California, Mexico.

We obtained near-IR spectroscopy of the luminous IR SPIRITS transients at several epochs using the Folded-port InfraRed Echellette spectrograph (FIRE) on the Magellan Baade Telescope at LCO, MOSFIRE on the Keck I Telescope, the Near-Infrared Echellette Spectrometer (NIRES) on the Keck II Telescope, the Gemini Near-InfraRed Spectrograph (GNIRS) on the 8.1m Gemini N Telescope (PIDs GN-2016B-FT-25, GN-2017B-Q-14; PI J. Jencson), and the FLAMINGOS-2 spectrograph on the 8.1m Gemini S Telescope (PID GS-2017B-Q-15; PI J. Jencson). Optical spectroscopy was obtained for SPIRITS 16tn, SPIRITS 17pc, and SPIRITS 17qm with the Low Resolution Imaging Spectrometer (LRIS) on the Keck I telescope.

(7 data files).