The figure above depicts distance modulus versus redshift for a subset of the Hawai’i Supernova Flows sample with colors indicating predicted peculiar velocity from the 2M++ model. This survey will directly measure the component of Hubble scatter from peculiar velocities. UKIRT’s NIR coverage should reduce distance scatter by up to 30% and substantially reduce systemic uncertainties from dust reddening.
Redder than Red: Discovery of an Exceptionally Red L/T Transition Dwarf (Schneider A. et al., 2023, ApJ, 943L..16)
UKIRT has discovered a free-floating planetary mass brown dwarf, J050626.96+073842.4 (pictured above). J050626.96+073842.4 has the reddest known colors of any brown dwarf around L/T transition — young and very dusty atmosphere. Below is photometric data from the UHS survey and the USNO-UKIRT parallax.
Detection of an Earth-sized exoplanet orbiting the nearby ultracool dwarf star SPECULOOS-3 (Gillon, M. et al. 2024, NatAs, 8, 865)
UKIRT has assisted in the discovery of SPECULOOS-3 b—an earth-sized exoplanet in a 17 hour orbit around an M6.5-type dwarf star 16.8 parsecs away. A K-band transit light curve was obtained from UKIRT using the UKIRT Wide Field Camera (WFCAM) on two epochs. The exoplanet is suitable for spectroscopic studies from JWST.
Pictured above are the phase-folded transit light curves of SPECULOOS-3 b. The purple light curve at the bottom shows the K-band photometry obtained using UKIRT and WFCAM.
From the UHS, UKIRT has ascertained the positions, photometry and proper motions for 966 known Brown Dwarfs. The measured proper motions are more precise than those from CatWISE and Pan-STARRS, but not Gaia – a valuable resource for non-Gaia point sources. The figure below is a comparison between the proper motion measurements and those from Gaia, CatWISE, and Pan-STARRS.
Eight New Substellar Hyades Candidates from the UKIRT Hemisphere Survey (Schneider A. et al., 2024, AJ, 168, 165)
Using UKIRT Hemisphere Survey (UHS) data along with UKIDSS GPS and GCS data, and CatWise 2020 data, eight new substellar candidates in the Hyades cluster. All of these objects have been confirmed to be L6-T8 Brown Dwarfs with Gemini-GNIRS spectroscopy. The discovery of these objects has increased the number of T dwarfs in Hyades by 50%!
The DEHVILS in the details: Type Ia supernova Hubble residual comparisons and mass step analysis in the near-infrared (Peterson E. et al., 2024, A&A, 690, A56)
DEHVILS is the largest published NIR sample with consistent coverage of maximum light across three NIR bands (Y, J, H).
Type Ia supernova (SN Ia) distance measurements depend on the properties of their host galaxies, and recent work suggests that the diversity of reddening laws in SN host galaxies may be responsible. In UKIRT’s NIR bands, SN distances are less sensitive to dust and therefore this paper tests whether the mass step persists in these bands. It found: (i) further evidence for improved Hubble residuals in the NIR, (ii) the existence (or nonexistence) of the mass step in the NIR cannot be concluded upon at this time (even though others have claimed it can be), and (iii) Hubble residuals in the NIR and optical are well-correlated.
The figure above compares simulated mass steps with different dust assumptions to the data from DEHVILS (left) and previous work (right). The simulation values show the effect of achromatic SN scatter (blue) and scatter due to a spread in dust reddening models (orange), and are the same in both panels. The shaded regions show 1σ uncertainties from the data.
Conducted by the US Naval Observatory (USNO) in partnership with the UH IfA, Cambridge Astronomical Survey Unit, and the Wide-Field Astronomy Unit, ROE, Edinburgh using the UKIRT Wide Field Camera (WFCAM) covering the northern sky from 0 — +60° in declination (12,700 sq. degrees), UHS has data releases in J and more recently K-bands. Surveys done in H-band are nearly complete with a new survey of Y-band and a reobservation in J-band starting in late 2023. Regions previously covered in the UKIDSS sky survey have been excluded in the current rounds of the UHS survey.
The productivity of an observatory is traditionally measured by the number of refereed articles containing observatory data. For the past three years running, UKIRT has set new productivity records as results from the UKIDSS survey have appeared in print (see here).
This trend is continuing. In the first four months of 2012, 76 papers based on UKIRT data appeared in the literature. If this rate is maintained, the publication rate for 2012 will smash the previous record by a very wide margin (see figure below).
The specific criteria for inclusion in the UKIRT publication list can be found here.
A research institute in South Korea, the Korean Astronomy and Space Science Institute (KASI), has acquired 22 nights of UKIRT time in 2012.
The science project to be carried out during this time is the UKIRT Widefield Infrared Survey for Fe+. The objective of this programme is to map 110 square degrees of the galactic plane using a bespoke Fe+ filter, to be supplied by KASI. Emission from Fe+ is a good tracer of dense, shock-excited gas, and the programme will therefore provide valuable insight into star formation and stellar feedback mechanisms. This survey will complement the existing UKIRT Widefield Infrared Survey for H2, and when taken together these data will probe dynamically-active components of star-forming regions, the circumstellar medium around evolved stars and the interstellar medium. The survey will also complement existing or upcoming surveys (e.g., UKIDSS-GPS, Spitzer-GLIMPSE, Spitzer-MIPSGAL, Akari, Herschel Hi-Gal, JCMT JPS). The project team includes collaborating astronomers from Korea and around the world, including two science staff at the Joint Astronomy Centre.
KASI is the second Korean organisation to obtain time on UKIRT, the first being the Centre for the Exploration of the Origin of the Universe, a research group at Seoul National University. Together, the two groups will have access to 62 nights of observing time in 2012.
15 March 2011 – UKIRT Sets New Productivity Record
Like all observatories, we routinely track the number of published scientific papers each year based on UKIRT data. This metric is a measure of the observatory’s productivity. The specific criteria we adopt for this determination are listed here.
In 2010, UKIRT set a new record with 118 publications in the scientific literature. This exceeds the previous record of 84, set in 1997 and repeated in 2009, by a very wide margin. The primary reason for the rapid increase in productivity is the UKIRT Infrared Deep Sky Survey (UKIDSS), which now takes up the lion’s share of UK time on UKIRT. Observations for UKIDSS commenced in 2005 and the publication of scientific results has been accelerating since the first paper appeared in 2007, as indicated in the figure below.
The complete record of UKIRT publications is given here and the UKIDSS-specific papers are listed by the UKIDSS consortium here.
