NOAO Research Articles

Searching for precursor activity of Type IIn Supernovae

We conducted a search for luminous outbursts prior to the explosion of Type IIn supernovae (SNe IIn). We built a sample of 27 objects spectroscopically classified as SNe IIn and all located at $z<0.015$. Using deep archival SN fields images ---taken up to nearly 20 years prior to the SN explosions themselves--- from transient surveys (PTF, ZTF, DES and CHASE) and major astronomical observatories (European Southern Observatory, ESO and National Optical Astronomy Observatory, NOAO), we found at least one outburst years to months before the explosion of seven SNe IIn, with the earliest precursor being 10 years prior to the explosion of SN 2019bxq. The maximum absolute magnitudes of the outbursts range between $-$11.5 mag and $-$15 mag, and the eruptive phases last for a few weeks to a few years. The $g-r$ colour measured for three objects during their outburst is relatively red, with $g-r$ ranging between 0.5 and 1.0 mag. This is similar to the colour expected during the eruptions of luminous blue variables. We note that the light curves of SNe with pre-SN outbursts have faster decline rates than those of the SNe that do not show pre-SN outbursts. SN 2011fh is remarkable, as it is still visible 12 years after the luminous SN-like event, indicating that the progenitor possibly survived, or that the interaction is still ongoing. We detect precursor activity in 29<!PCT!> of bona fide SNe IIn in our sample. However, a quantitative assessment of the observational biases affecting the sample suggests that this fraction is an underestimation of the intrinsic precursor occurrence rate.

Mass Ratio of Single-line Spectroscopic Binaries with Visual Orbits Using Bayesian Inference and Suitable Priors* *Based in part on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia, e Inovaçãoes (MCTI) da República Federativa do Brasil, the U.S. National Optical Astronomy Observatory (NOAO), the University of North Carolina at

We present orbital elements for 22 single-line binaries, nine of them studied for the first time, determined from a joint spectroscopic and astrometric solution. The astrometry is based on interferometric measurements obtained with the HRCam Speckle camera on the SOAR 4.1 m telescope at Cerro Pachon, Chile, supplemented with historical data. The spectroscopic observations were secured using Echelle spectrographs (FEROS, FIDEOS, and HARPS) at La Silla, Chile. A comparison of our orbital elements and systemic velocities with previous studies, including Gaia radial velocities, shows the robustness of our estimations. By adopting suitable priors of the trigonometric parallax and spectral type of the primary component, and using a Bayesian inference methodology developed by our group, we were able to estimate mass ratios for these binaries. Combining the present results with a previous study of other single-line binaries from our team, we present a pseudo mass-to-luminosity relationship based on 23 systems (46 stars) in the mass range 0.6 ≤ M ⊙ ≤ 2.5. We find a reasonable correspondence with a fiducial mass-to-luminosity relationship. We conclude that our methodology does allow us to derive tentative mass ratios for these types of binaries.

WIYN Open Cluster Study 89. M48 (NGC 2548) 2: Lithium Abundances in the 420 Myr Open Cluster M48 from Giants through K Dwarfs* * The WIYN Observatory is a joint facility of the University of Wisconsin−Madison, Indiana University, the National Optical Astronomy Observatory, and the University of Missouri. † †WIYN Open Cluster Study, Mathieu ().

We consider WIYN/Hydra spectra of 329 photometric candidate members of the 420 Myr old open cluster M48 and report lithium detections or upper limits for 234 members and likely members. The 171 single members define a number of notable Li-mass trends, some delineated even more clearly than in Hyades/Praesepe: the giants are consistent with subgiant Li dilution and prior MS Li depletion due to rotational mixing. A dwarfs (8600–7700 K) have upper limits higher than the presumed initial cluster Li abundance. Two of five late A dwarfs (7700–7200 K) are Li-rich, possibly due to diffusion, planetesimal accretion, and/or engulfment of hydrogen-poor planets. Early F dwarfs already show evidence of Li depletion seen in older clusters. The Li–T eff trends of the Li Dip (6675–6200 K), Li Plateau (6200–6000 K), and G and K dwarfs (6000–4000 K) are very clearly delineated and are intermediate to those of the 120 Myr old Pleiades and 650 Myr old Hyades/Praesepe, which suggests a sequence of Li depletion with age. The cool side of the Li Dip is especially well defined with little scatter. The Li–T eff trend is very tight in the Li Plateau and early G dwarfs, but scatter increases gradually for cooler dwarfs. These patterns support and constrain models of the universally dominant Li depletion mechanism for FGK dwarfs, namely rotational mixing due to angular momentum loss; we discuss how diffusion and gravity-wave-driven mixing may also play roles. For late G/K dwarfs, faster rotators show higher Li than slower rotators, and we discuss possible connections between angular momentum loss and Li depletion.

Molecular dynamics simulation and experimental validation on the interfacial diffusion behaviors of rejuvenators in aged bitumen

This study aims to multiscale investigate the effects of rejuvenator type, temperature, and aging degree of bitumen on the diffusion behaviors of rejuvenators (bio-oil BO, engine-oil EO, naphthenic-oil NO, and aromatic-oil AO) in aged binders. The molecular dynamics (MD) simulation method is performed to detect the molecular-level diffusion characteristics of rejuvenators and predict their diffusion coefficient (D) parameters. At an atomic scale, the mutual but partial interfacial diffusion feature between rejuvenators and aged bitumen molecules is observed. Moreover, Fick's Second Law well fits the concentration distribution of rejuvenator molecules in aged bitumen. The magnitude for D values of four rejuvenators varies from 10-11 to 10-10 m2/s, and the diffusive capacity order is BO > EO > NO > AO. Meanwhile, diffusion tests and dynamic shear rheometer (DSR) characterizations are employed to validate the MD simulation outputs. The experimental results in magnitude and order of D values agree well with MD simulation outputs. Lastly, the increased aging degree of bitumen exhibits a negative impact on the molecular diffusivity of BO, EO, and NO rejuvenators, while the D value of AO molecules enlarges as the aging level deepens. The underlying mechanism may be composed of the free volume fraction in aged bitumen and the intermolecular force between rejuvenator and aged bitumen molecules, which differs remarkably for various rejuvenators.

Optimal Observational Scheduling Framework for Binary and Multiple Stellar Systems* *Based in part on observations obtained at the international Gemini Observatory, a program of NSF's NOIRLab, which is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation on behalf of the Gemini Observatory partnership: the National Science Foundation (United

The optimal instant of observation of astrophysical phenomena for objects that vary on human timescales is an important problem, as it bears on the cost-effective use of usually scarce observational facilities. In this paper, we address this problem in the case of tight visual binary systems through a Bayesian framework based on the maximum entropy sampling principle. Our proposed information-driven methodology exploits the periodic structure of binary systems to provide a computationally efficient estimation of the probability distribution of the optimal observation time. We show the optimality of the proposed sampling methodology in the Bayes sense and its effectiveness through direct numerical experiments. We successfully apply our scheme to the study of two visual-spectroscopic binaries and one purely astrometric triple hierarchical system. We note that our methodology can be applied to any time-evolving phenomena, a particularly interesting application in the era of dedicated surveys, where a definition of the cadence of observations can have a crucial impact on achieving the science goals.

Bayes-based Orbital Elements Estimation in Triple Hierarchical Stellar Systems* * Released on 2019 June 10th. † † Based partially on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia, e Inovação (MCTI) da República Federativa do Brasil, the U.S. National Optical Astronomy Observatory (NOAO), the University of North Carolina

Under certain rather prevalent conditions (driven by dynamical orbital evolution), a hierarchical triple stellar system can be well approximated, from the standpoint of orbital parameter estimation, as two binary star systems combined. Even under this simplifying approximation, the inference of orbital elements is a challenging technical problem because of the high dimensionality of the parameter space, and the complex relationships between those parameters and the observations (astrometry and radial velocity). In this work, we propose a new methodology for the study of triple hierarchical systems using a Bayesian Markov-Chain Monte Carlo-based framework. In particular, graphical models are introduced to describe the probabilistic relationship between parameters and observations in a dynamically self-consistent way. As information sources we consider the cases of isolated astrometry, isolated radial velocity, as well as the joint case with both types of measurements. Graphical models provide a novel way of performing a factorization of the joint distribution (of parameter and observations) in terms of conditional independent components (factors), so that the estimation can be performed in a two-stage process that combines different observations sequentially. Our framework is tested against three well-studied benchmark cases of triple systems, where we determine the inner and outer orbital elements, coupled with the mutual inclination of the orbits, and the individual stellar masses, along with posterior probability (density) distributions for all these parameters. Our results are found to be consistent with previous studies. We also provide a mathematical formalism to reduce the dimensionality in the parameter space for triple hierarchical stellar systems in general.

Data Lab—A community science platform

Abstract Data Lab is an open-access science platform developed and operated by the Community and Science Data Center (CSDC) at NSF’s National Optical-Infrared Astronomy Research Laboratory (NOIRLab). It serves public photometric survey datasets, provides interactive and programmatic data access, and SQL/ADQL query capabilities via TAP. Users also receive generous storage allocations with VOSpace and MyDB, co-located with our data holdings. A host of services such as cross-matching, image cutouts via SIA, file services for survey data, and a Jupyter notebook interface for analysis close to the data complement the mission statement. Launched in 2017 at the National Optical Astronomy Observatory, Data Lab supports a base of over 1,300 registered users, processes on average 15,000 queries daily, serves over 50 TB of photometric catalogs, and provides access to over 2 PB of survey image products at NOIRLab’s Science Data Archive. Future development will include support for massive spectroscopic datasets and for processing of alert streams generated by e.g. ZTF and LSST. Users will also be able to create and administrate ad hoc user groups for shared data access and scientific analysis, and will enjoy containerized services and notebook spaces.

Imaging and Analysis of Neon Nova V382 Vel Shell**Based on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia, Inovação e Comunicações (MCTIC) da República Federativa do Brasil, the U.S. National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU).

We present the detection and imaging of the spatially resolved shell of nova V382 Vel with SOAR adaptive optics module (SAM). The shell was observed in narrow-band filters Hα and [O III] 5007 Å revealing different structures in each filter. The shell’s angular diameter obtained was 9.9 arcsec, equivalent to 2.8 × 1017 cm, using the distance of 1.79 kpc obtained by the Gaia mission. The upper limit for total shell mass derived from recombination lines is Ms = 1.4 × 10−4 M⊙. Our photoionization models indicate an accretion disk with Td = 60,000 K and L = 1036 erg/s as main ionizing source.

Effect of Active Galactic Nuclei (AGN) on the Photometric and Morphologic Properties of NGC 4414 and NGC 4369 Spiral Galaxies

The purpose of this work is to clarify the effect of the Active Galactic Nucleus (AGN) on the properties of the galaxy. A photometric study of two galaxies by surface optical measurements techniques and by using'griz filters' was performed. The scientific material that used in this work was obtained from ''SLOAN DIGITAL SKY SURVEY'' (DR7), a fuzzy color, contour maps, photometric parameters, and color indices were studied by using surface photometric technique. The work was done by Ellipse task in IRAF (Image Reduction and Analysis Facility) software from the National Optical Astronomy Observatory (NOAO).

Outcomes from the IYL2015 Quality Lighting Teaching Kit Program: Reaching for the Stars

Poor quality lighting not only impedes astronomy research and our right to see a starry night sky, but creates safety issues, affects human circadian sensitivities, disrupts ecosystems, and wastes billions of dollars/year in energy consumption. It also leads to excess carbon emissions. How do you change the mindset of society that is used to turning night into day? You educate the next generation on quality lighting. As an outcome of the International Year of Light 2015, the U.S. National Optical Astronomy Observatory’s Education and Public Outreach group has produced a Quality Lighting Teaching (QLT) Kit. The kits are designed around problem-based learning scenarios. The kit’s six activities allow students to address real lighting problems that relate to wildlife, sky glow, aging eyes, energy consumption, safety, and light trespass. The activities are optimized for 11-14 year olds, but can be expanded to younger and older. All materials are in English and Spanish. Most of the activities can be done within in a few minutes during class or afterschool in the form of stations or as stand-alones. Everything one needs for the six activities is included. Tutorial videos on how to do the activities can be found at www.noao.edu/education/qltkit.php. Ninety-two kits have been distributed to 32 countries with the help of SPIE–The International Society for Optical Engineering, CIE–International Commission on Illuminations, OSA–The Optical Society, IDA–the International Dark Sky Association, and the IAU OAD–Office of Astronomy Development. Highlights from the initial program evaluation will be discussed.

The Quality Lighting Teaching Kit: Utilizing Problem-Based Learning in Classrooms

AbstarctThe U.S. National Optical Astronomy Observatory’s Education and Public Outreach group has produced a Quality Lighting Teaching Kit. The kits are designed around problem-based learning scenarios. The kit’s six activities allow students to address real lighting problems that relate to wildlife, sky glow, aging eyes, energy consumption, safety, and light trespass. The activities are optimized for 11-16 year olds. As part of the IAU100 celebration, the kits will be manufactured and made available to observatories and communities around the world.

Photometric investigations of NGC 2577 and NGC 4310 Lenticular Galaxies

In this study, two lenticular galaxies ( NGC 2577, NGC 4310 ) have been chosen to study their morphological and photometric properties, by using The [1] IRAF ISOPHOTE ELLIPSE task with griz -Filters. Observations are obtained from the Sloan Digital Sky Survey (SDSS) which are reach now to the Data Release (DR14). The data reduction of all images (bias and flat field) have been done by SDSS pipeline. The surface photometric investigations were performed like the total magnitude, together with isophotal contour maps, Surface brightness profiles and a bulge/disk decomposition of the images of the galaxies, although the disk position angle, ellipticity and inclination of the galaxies have been done. [1] IRAF is distributed by the National Optical Astronomy Observatories, which is operated by the Association of Universities for Research in Astronomy, Inc., under cooperative agreement with the National Science Foundation.

The First Data Release from SweetSpot: 74 Supernovae in 36 Nights on WIYN+WHIRC

Abstract SweetSpot is a 3 yr National Optical Astronomy Observatory (NOAO) survey program to observe Type Ia supernovae (SNe Ia) in the smooth Hubble flow with the WIYN High-resolution Infrared Camera (WHIRC) on the WIYN 3.5 m telescope. We present data from the first half of this survey, covering the 2011B–2013B NOAO semesters and consisting of 493 calibrated images of 74 SNe Ia observed in the rest-frame near-infrared (NIR) in the range 0.02 < z < 0.09. Because many observed supernovae require host-galaxy subtraction from templates taken in later semesters, this release contains only the 186 NIR (JHK s ) data points for the 33 SNe Ia that do not require host-galaxy subtraction. The sample includes four objects with coverage beginning before the epoch of B-band maximum and 27 beginning within 20 days of B-band maximum. We also provide photometric calibration between the WIYN+WHIRC and Two Micron All-Sky Survey (2MASS) systems, along with light curves for 786 2MASS stars observed alongside the SNe Ia. This work is the first in a planned series of three SweetSpot Data Releases. Future releases will include the full set of images from all 3 yr of the survey, including host-galaxy reference images and updated data processing with host-galaxy reference subtraction. SweetSpot will provide a well-calibrated sample that will help improve our ability to standardize distance measurements to SNe Ia, examine the intrinsic optical–NIR colors of SNe Ia at different epochs, explore the nature of dust in other galaxies, and act as a stepping-stone for more distant, potentially space-based surveys.

The NOAO Publications Tracking Program: Developing Policies & Procedures for Usage, Acknowledgment, and Citation of Data

The National Optical Astronomy Observatory (NOAO) has a complex publications tracking program, which is coordinated by the NOAO Librarian. We track publications that use data from multiple observatories (Kitt Peak National Observatory [KPNO] in Tucson, Arizona, and Cerro Tololo Inter-American Observatory [CTIO] in La Serena, Chile, as well as non-NOAO telescopes to which we grant community access at other observatories); multiple telescopes and instruments; multiple observing programs, including survey programs; and multiple datasets in the Science Data Archive (SDA) at NOAO. The growing SDA and new user services, such as the Data Lab, ensure that the use of NOAO archival datasets will become even more widespread and important for scientific discovery and research. Accurate and complete publication tracking is essential for reporting to our funding agencies, developing our programs, and determining our scientific contributions and impact. Setting policies to guide authors in specifying and acknowledging usage of NOAO data is an essential element in our ability to determine and document relevant publications. Developing systems to track the use of our telescope data and archival datasets is another critical element. New policies to track the use of our telescope data are being developed, new systems to track the use and reuse of datasets within our particular institutional context are being explored, and methods of linking our publications data with our dataset usage data are being devised. Updated policies for the proper and ethical usage, acknowledgement, and citation of our archival data are being written and reviewed.

The Quality Lighting Teaching Kit: Inspiring our Society to be Part of the Solution to Light Pollution

As an outcome of the International Year of Light 2015, the U.S. National Optical Astronomy Observatory’s Education and Public Outreach group has produced a Quality Lighting Teaching (QLT) Kit, The kits are designed around problem-based learning scenarios. The kit’s six activities allow students to address real lighting problems that relate to wildlife, sky glow, aging eyes, energy consumption, safety, and light trespass. The activities are optimized for 11-14 year olds but can be expanded to younger and older. Most of the activities can be done within in a few minutes during class or afterschool and as stations or as stand-alones. Everything you need for the six activities is included in the kit. Tutorial videos on how to do the activities can be found at www.noao.edu/education/qltkit.php. 90 out of 100 kits have been distributed to SPIE, OSA, CIE, IDA and the IAU in 32 countries.

Extragalactic survey aims to shed light on dark energy

Robot-controlled optical fibers will help create 3D map of the cosmos.

Photometric and Spectroscopic Survey of the Cluster [DBS2003] 156 Associated with the H II Region G331.1−0.5☆☆Based on observations obtained at the Southern Observatory for Astrophysical Research (SOAR), a joint project of the Ministério de Ciência, Tecnologia e Inovação (MCTI) of the República Federativa do Brasil, the U.S. National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill

The Norma section of the Milky Way is especially interesting because it crosses three spiral arms: Sagittarius–Carina, Scutum–Crux and the Norma arm itself. Distance determinations of embedded young stellar clusters can contribute to define the spiral structure in this part of the Galaxy. However, spectrophotometric distances were obtained for only a few of these clusters in Norma. We present a photometric and spectroscopic study in the NIR of the [DBS2003] 156 stellar cluster, associated with the H II region G331.1−0.5. We aim to find the ionizing sources of the H II region and determine its distance. The cluster was observed in the J, H, and bands and eight potential massive stars were chosen among the detected sources according to color criteria; subsequent spectroscopy of these candidates was performed with the Ohio State Infrared Imager/Spectrometer spectrograph attached to the Southern Observatory for Astrophysical Research 4.1 m telescope. We identified and classified spectroscopically four early-type stars: IRS 176 (O8 V), IRS 308 (O-type), IRS 310 (O6 V), and IRS 71 (B1 Iab). Based on the proximity of IRS 176 and 308 with the radio continuum emission peaks and their relative positions with respect to the warm dust mid-infrared emission, we concluded that these two stars are the main ionizing sources of the H ii region G331.1−0.5. The mean spectrophotometric distance of IRS 176 and 310 of 3.38 ± 0.58 kpc is similar to that obtained in a previous work for two early-type stars of the neighbor cluster [DBS2003] 157 of 3.29 ± 0.58 kpc. The narrow range of radial velocities of radio sources in the area of the clusters [DBS2003] 156 and 157 and their similar visual extinction indicate that these clusters are physically associated. A common distance of 3.34 ± 0.34 kpc is derived for the system [DBS2003] 156 and 157.

INTERNATIONAL COLLABORATION FOR SILICON CARBIDE MIRROR POLISHING AND DEVELOPMENT

For research and development of Silicon Carbide (SiC) mirrors, the Korea Astronomy and Space Science Institute (KASI) and National Optical Astronomy Observatory (NOAO) have agreed to cooperate and share on polishing and measuring facilities, experience and human resources for two years (2014-2015). The main goals of the SiC mirror polishing are to achieve optical surface figures of less than 20 nm rms and optical surface roughness of less than 2 nm rms. In addition, Green Optics Co., Ltd (GO) has been interested in the SiC polishing and joined the partnership with KASI. KASI will be involved in the development of the SiC polishing and the optical surface measurement using three different kinds of SiC materials and manufacturing processes (POCO TM , CoorsTek TM and SSG TM corporations) provided by NOAO. GO will polish the SiC substrate within requirements. Additionally, the requirements of the optical surface imperfections are given as: less than 40 um scratch and 500 um dig. In this paper, we introduce the international collaboration and interim results for SiC mirror polishing and development.

COSMIC SHEAR RESULTS FROM THE DEEP LENS SURVEY. I. JOINT CONSTRAINTS ON ΩMAND σ8WITH A TWO-DIMENSIONAL ANALYSIS

We present a cosmic shear study from the Deep Lens Survey (DLS), a deep BVRz multi-band imaging survey of five 4 sq. degree fields with two National Optical Astronomy Observatory (NOAO) 4-meter telescopes at Kitt Peak and Cerro Tololo. For both telescopes, the change of the point-spread-function (PSF) shape across the focal plane is complicated, and the exposure-to-exposure variation of this position-dependent PSF change is significant. We overcome this challenge by modeling the PSF separately for individual exposures and CCDs with principal component analysis (PCA). We find that stacking these PSFs reproduces the final PSF pattern on the mosaic image with high fidelity, and the method successfully separates PSF-induced systematics from gravitational lensing effects. We calibrate our shears and estimate the errors, utilizing an image simulator, which generates sheared ground-based galaxy images from deep Hubble Space Telescope archival data with a realistic atmospheric turbulence model. For cosmological parameter constraints, we marginalize over shear calibration error, photometric redshift uncertainty, and the Hubble constant. We use cosmology-dependent covariances for the Markov Chain Monte Carlo analysis and find that the role of this varying covariance is critical in our parameter estimation. Our current non-tomographic analysis alone constrains the Omega_M-sigma_8 likelihood contour tightly, providing a joint constraint of Omega_M=0.262+-0.051 and sigma_8=0.868+-0.071. We expect that a future DLS weak-lensing tomographic study will further tighten these constraints because explicit treatment of the redshift dependence of cosmic shear more efficiently breaks the Omega_M-sigma_8 degeneracy. Combining the current results with the Wilkinson Microwave Anisotropy Probe 7-year (WMAP7) likelihood data, we obtain Omega_M=0.278+-0.018 and sigma_8=0.815+-0.020.

Astronomy Education Review: An Afterword

This October would have marked the 12th anniversary of the first paper published in a new on-line journal called Astronomy Education Review (AER). Instead of celebrating that anniversary, however, it appears that we must face the fact that the journal will cease publication in its present form. After taking over the journal from its founding editors (Sidney Wolff and Andrew Fraknoi) and its founding publisher (the National Optical Astronomy Observatories) and subsidizing and publishing the journal for five years, the Council of the American Astronomical Society (with the advice of its Publications Board) decided that AER had too few papers, too few readers, and covered astronomy education too narrowly to be supported by the Society, with only a very small contribution from the Astronomical Society of the Pacific and a few small donations as outside income.