APOGEE-South: Plate-Pluggers and Tripods – APOGEE-Sur: Conexión de Placas y Trípodes

Recently, a small group of astronomers from Chile has been visiting Apache Point Observatory. Their job will be to assist with operations at APOGEE-South, which is being built for the Irénée du Pont telescope at Las Campanas Observatory. Introducing: Christian Nitschelm, a faculty member at Universidad de Antofagasta; Andrés Almeida, a Masters student from Universidad Andrés Bello; and Jaime Vargas, Masters student at Universidad de La Serena.

Recientemente, un pequeño grupo de astrónomos de Chile ha estado visitando el Observatorio Apache Point (APO por sus siglas en Inglés). Su trabajo consistirá en ayudar con las operaciones en APOGEE-Sur, que se está construyendo para el telescopio Irénée du Pont en el Observatorio Las Campanas. Presentamos a: Christian Nitschelm, profesor en la Universidad de Antofagasta; Andrés Almeida, un estudiante de Maestría de la Universidad Andrés Bello; y Jaime Vargas, estudiante de Maestría de la Universidad de La Serena.

Jamie (left) Christian (center), and Andres (right), unplugging an APOGEE plate after observations. Jamie (a la izquierda), Christian (al centro), y Andrés (a la derecha), desconectando las fibras ópticas de una placa de APOGEE después de las observaciones.

Jamie (a la izquierda), Christian (al centro), y Andrés (a la derecha), desconectando una placa de APOGEE después de las observaciones.
Jamie (left) Christian (center), and Andres (right), unplugging an APOGEE plate after observations.

While at APO, Jamie, Christian, and Andres are learning a number of important skills that they will take back to Las Campanas Observatory. This includes plugging and unplugging plates:

Mientras tanto en el APO, Jamie, Christian y Andrés están aprendiendo una serie de técnicas importantes que llevarán al Observatorio Las Campanas. Esto incluye conectar y desconectar las placas:

Christian and Jamie seen here plugging fibers into a plug plate. Christian y Jaime se ven aquí conectando las fibras en una placa de conexión.

Christian y Jaime se ven aquí conectando las fibras ópticas en una placa de conexión.
Christian and Jamie seen here plugging fibers into a plug plate.

They are also learning to use the new Mock Up and Training Facility tripod, cartridge, and dolly (seen below). This setup will be sent down to Universidad de La Serena so that this crew can train future support staff.

También están aprendiendo a usar la maqueta y trípode de capacitación, el cartucho y carro (observados a continuación). Esta configuración se enviará a la Universidad de La Serena para que este equipo de trabajo pueda entrenar el personal de apoyo futuro.

Christian and Jamie swapping out a plug plate cartridge with the Mock Up and Training Facility tripod (the big steel frame), cartridge (the blue object suspended from the tripod) and dolly, which will be used to transport plug plates to and from the telescope. Christian y Jaime intercambiando el cartucho de la placa conexión con la maqueta y el trípode de capacitación (la estructura de acero grande), el cartucho (el objeto azul suspendido del trípode) y el carro, que será utilizado para transportar las placas de conexión hacia y desde el telescopio.

Christian y Jaime intercambiando el cartucho de la placa conexión con la maqueta y el trípode de capacitación (la estructura de acero grande), el cartucho (el objeto azul suspendido del trípode) y el carro, que será utilizado para transportar las placas de conexión hacia y desde el telescopio.
Christian and Jamie swapping out a plug plate cartridge with the Mock Up and Training Facility tripod (the big steel frame), cartridge (the blue object suspended from the tripod) and dolly, which will be used to transport plug plates to and from the telescope.

“Torquing” the plug plate slightly is a necessary skill so that it aligns with the field of curvature of the telescope. Using a ring around the plate (shown being attached below), the plate can be bent ever so slightly:

“Torcer” ligeramente la placa de conexión es una habilidad necesaria para alinear la placa con el campo de curvatura del telescopio. Usando un anillo alrededor de la placa (mas abajo se ve como se engancha), ésta se puede doblar ligeramente:

Christian and Andres attaching the bending ring around the plate. Christian y Andrés enganchan el anillo de flexión alrededor de la placa.

Christian y Andrés enganchan el anillo de flexión alrededor de la placa.
Christian and Andres attaching the bending ring around the plate.

And, of course, it is important to check your work. In this case, a computer is used to map the locations of fibers on the plate, ensuring that they will be on target when the plug plate is used on the telescope:

Y, por supuesto, es importante revisar su trabajo. En este caso, se utiliza un ordenador para mapear las ubicaciones de fibras en la placa, asegurando que van apuntar al objeto cuando la placa de conexión se use en el telescopio:

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Christian utiliza una computadora para medir el perfil de la placa de conexión después de que ha sido mapeada. Esto asegurará que la placa ha sido “torcida” correctamente.
Christian using a computer to measure the profile of the plug plate after it has been mapped. This will ensure that they have “torqued” the plate properly.

Jamie is enjoying his new skills set! Here, he is drawing an overlay on a plug plate to prepare it for plugging. ¡Jaime disfruta de sus nuevas habilidades! Aquí está dibujando una superposición en una placa de conexión para prepararla para la conexión.

¡Jaime disfruta de sus nuevas habilidades! Aquí está dibujando una superposición en una placa de conexión para prepararla para la conexión.
Jamie is enjoying his new skills set! Here, he is drawing an overlay on a plug plate to prepare it for plugging.

Engineering Work for APOGEE-South – Trabajo de ingenieria en APOGEE-Sur

Telescopes at LCO

The du Pont 2.5m telescope on the middle-left, and the pair of Magellan 6.5m telescopes on the right.
El telescopio de 2.5m du Pont al centro hacia la izquierda y los dos telescopios de 6,5m, Magallanes, a la derecha.

A half-dozen SDSS scientists and engineers traveled to Las Campanas Observatory, Chile at the beginning of March to continue work on characterizing the 2.5m du Pont telescope performance in preparation for the first APOGEE-South hardware tests in August. This report is from the SDSS Operations Software Manager John Parejko, who was part of the run (and ended up involved in some hardware tests, against his better judgement!). Translated into Spanish by Verónica Motta, Associate Professor of Astronomy at Valparaiso University.

Las Campanas Observatory currently hosts three “large” telescopes (greater than 2 meters diameter), and a number of 1 meter diameter and smaller telescopes. The 2.5m du Pont telescope (in use since 1977) is a much older telescope than the 2.5m Sloan telescope at APO (in use since 1999), but it is at an excellent site, its optics are still very good–I heard them referred to as “superb” on several occasions–and it has a large field of view. With the assistance of the telescope’s owners–the Carnegie Institution of Washington–SDSS plans to help design improvements to the telescope drive systems so that we can run an APOGEE-South survey and fully sample the Milky Way’s bulge.

Una media docena de científicos e ingenieros del SDSS viajaron al Observatorio Las Campanas (Chile) a principios de marzo para continuar el trabajo de caracterización del rendimiento del telescopio de 2.5m du Pont en preparación para la primera prueba de hardware de APOGEE-Sur que se realizara en agosto. Este informe proviene del Director de Operaciones de Software del SDSS, John Parejko, que participó en la ejecución (y que terminó involucrado en algunas pruebas de hardware, en contra de su mejor juicio ! ). Traducción de Verónica Motta, profesor asociado de astronomía en la Universidad de Valparaíso.

El Observatorio Las Campanas actualmente alberga tres “grandes” telescopios (mayores de 2m de diámetro), y varios más pequeños de hasta 1m de diámetro. El telescopio de 2.5m du Pont (en uso desde 1977) es más antiguo que el telescopio de 2.5m Sloan en el Observatorio Apache Point (APO, en uso desde 1999), pero está en un lugar excelente, su óptica es todavía muy buena -he oído referirse a ella como “excelente” en varias ocasiones- y tiene un gran campo de visión. Con la ayuda de los propietarios del telescopio -la Institución Carnegie de Washington- el SDSS planea ayudar a mejorar el diseño de los sistemas de accionamiento del telescopio de manera que podemos realizar el relevamiento APOGEE-Sur y muestrear completamente el bulbo de la  Vía Láctea.

Paul and Nick looking at the rotator

Paul Harding and Nick MacDonald looking at the rotator.
Nick MacDonald y Paul Harding investigan las propiedades físicas del rotador del du Pont.

In order to determine what improvements the telescope requires, we have to make precise measurements of how different parts of the telescope move. From previous work, we found that the Right Ascension and Declination motors (equivalent to latitude and longitude projected onto the sky) probably don’t need much work. This trip, we measured the motion of the rotator and focus systems. Carnegie is in the process of completing their own upgrades to the telescope, and our measurements will help guide these changes.

Con el fin de determinar qué mejoras necesita el telescopio tenemos que hacer mediciones precisas de cómo se mueven las diferentes partes del telescopio. A partir de trabajos anteriores, encontramos que los motores de la Ascensión Recta y de la Declinación (equivalentes a la latitud y a la longitud proyectada sobre el cielo) probablemente no necesitan mucho trabajo. En este viaje medimos el movimiento del rotador y del sostema de enfoque. Carnegie se encuentra en el proceso de terminar sus propias mejoras al telescopio y nuestras medidas servirán de guía para estos cambios.

Author self portrait in a primary. You can see the reflection of the secondary mirror and its light baffles just above my head.

Author self portrait in a primary. You can see the reflection of the secondary mirror and its light baffles just above my head.
Autorretrato del autor en el primario, se puede ver el reflejo del espejo secundario y su luz que pasa justo por encima de mi cabeza.

To focus a telescope like this one, you move the secondary mirror. Even tiny changes in the position or tilt of the secondary can result in incorrect or uneven focus when you need a large field of view, as APOGEE will. As the du Pont is an older telescope, the system that moves the secondary mirror may not be as stable as APOGEE requires.

We first checked whether the mirror moved the exact amount each time it was commanded. We’ve found that the mirror motors need to be more repeatable: moving 500 “up” and then 500 “down” should return to exactly the same place, but it doesn’t. The Carnegie engineers are now working to improve the motors and control systems to fix this.

Para enfocar un telescopio como éste se mueve el espejo secundario. Incluso pequeños cambios en la posición o en la inclinación del secundario pueden resultar en un foco incorrecto o irregular en un gran campo de visión como el que utilizará APOGEE. Como el telescopio du Pont es viejo, el sistema que mueve el espejo secundario puede no ser tan estable como requiere APOGEE.

Primero revisamos si el espejo se movió la cantidad correcta cada vez que se le ordenó. Hemos encontrado que los motores del espejo tienen que ser más confiables: moverse 500 hacia “arriba” y después 500 hacia “abajo” debería regresarlo exactamente al mismo lugar, pero no es así. Los ingenieros de Carnegie están trabajando para mejorar la motores y los sistemas de control para solucionar este problema.

Author self portrait in the du Pont secondary, with my camera and our measuring target visible.

Author self portrait in the du Pont secondary, with my camera and our measuring target visible.
Autorretrato del autor en el secundario del du Pont, con mi cámara y nuestro objeto de medición visible.

To measure any shift or tilt in the secondary, we used a rather interesting system: a typical camera (the Panasonic G2 that I travel with for touristy photos; it took all the pictures shown in this post) with a long telephoto lens mounted on a moveable rail, taking pictures of the image in the secondary mirror of a “target” on the floor. We then took pictures with the camera and measured whether the target moved around: if it doesn’t move from image to image, we know the secondary is very stable against tilts and shifts during movement. We’re still analyzing the results of these tests, and will use them to detail what changes need to be made.

Para medir cualquier desplazamiento o inclinación en el secundario usamos un método interesante: una cámara típica (la Panasonic G2 con la que viajo para tomar fotos turísticas; la que tomó todas las imágenes que se muestran aquí) con un teleobjetivo largo montado en un carril móvil, toma fotos de la imagen en el espejo secundario de un “objetivo” en el suelo. Entonces tomamos fotos con la cámara y medimos si el objetivo se movió: si no se mueve de imagen a imagen, sabemos que el secundario es muy estable ante las inclinaciones y los cambios durante el movimiento. Todavía estamos analizando los resultados de estas pruebas y las usaremos para detallar los cambios deben hacerse.

Además de mi trabajo de ingeniería en el telescopio du Pont, tuve tiempo durante la noche para fotografiar el cielo austral. Este fue mi primer viaje al hemisferio sur y me aseguré de levantarme temprano al menos una mañana para ver las Nubes Mayor y Menor de Magallanes y toda la gloria de la Vía Láctea austral. Tuve que levantarme temprano para evitar la Luna casi llena, que disminuye la visibilidad. Sin duda tienen cielos espectaculares ahí abajo.

In addition to my engineering work on the du Pont telescope, I was able to take some time at night to photograph the southern sky. This was my first trip to the southern hemisphere, and I made sure to get up early at least one morning to see the Large and Small Magellanic Clouds and the full glory of the southern Milky Way. I had to get up early in order to avoid the nearly-full moon, which otherwise much diminished the view. They’ve certainly got some spectacular skies down there!

The southern hemisphere Milky Way and Large Magellanic Cloud, over the main LCO building.

La Vía Láctea y las Nubes Mayor y Menor de Magallanes Nube en el hemisferio austral, sobre el edificio principal del LCO.
The southern hemisphere Milky Way and Large Magellanic Cloud, over the main LCO building.

Pasé mis últimos días de este viaje en la ciudad de La Serena, reunido con la gente de la Universidad de La Serena (ULS) y reuniendo los resultados de las pruebas. Durante este tiempo, pude ver como la escuela de ingeniería ULS  maniobró la nueva máquina, marca Mazak CNC, con cuidado hasta su lugar en el taller de mecánica. Las instituciones chilenas han utilizado la colaboración SDSS/Chile para reforzar su infraestructura a través de subvenciones y varios acuerdos. En este caso, fueron capaces de comprar el modelo más avanzado de fresadora computarizada que planean utilizar para construir piezas para APOGEE-Sur.Tengo ganas de ver que pueden construir con ella!

I spent my last days of this trip in the city of La Serena, meeting with people at the University de La Serena (ULS) and collating results from the tests. During this time, I was on hand to watch as the ULS engineering school had a brand new Mazak CNC machine carefully maneuvered into place in their machine shop. Chilean institutions have used the SDSS/Chile collaboration to bolster their on-site infrastructure via grants and various agreements. In this case they were able to purchase a state-of-the- art computerized milling machine that they plan to use to construct parts for APOGEE-South. It will also provide engineering student training and experience, and allow the university to construct other cutting edge scientific equipment in the future.

I’m looking forward to see what they can build with it!

Happy Engineers standing in front of their just-delivered CNC machine. Ingenieros felices de pie frente a su recién entregada máquina CNC.

Ingenieros felices de pie frente a su recién entregada máquina CNC.
Happy Engineers standing in front of their just-delivered CNC machine.

Job Posting: University of Washington Machine Shop Manager

The University of Washington Physics Instrument Shop is looking for a new shop manager.  This is the machine shop which builds the SDSS plug plates, fiber systems, and a number of our other instrumentation and telescope equipment for SDSS, APO 3.5 m, and soon LCO. This shop is a key part of SDSS operations.

Position Description

The Instrument Shop Manager is responsible for the daily operations of a 5 FTE research and development machine shop with an $850,000 annual budget.  The Instrument Shop provides clients (primarily scientists) with both one-of-a-kind and production instruments.  The manager is solely responsible for assessing each client’s request, estimating the amount of time and effort to complete the job, assigning the job to the staff persons whose abilities and experience best fit the request and scheduling the job.  The Manager is the line supervisor for 5 FTE – selecting, hiring, evaluating and disciplining employees as necessary.   The Manager ensures that the proper tooling and materials are on hand for each job, that machines are maintained and repaired and that the workplace is safe. The Manager works closely with faculty, staff and students on their research projects.  Many experiments involve instruments that are not available ‘off the shelf’ and are custom designed for each particular experiment or project.  Faculty, staff and students depend upon the Manager to review their ideas and ensure that the devices are buildable and suggest modifications that may result in a better instrument or make it easier to produce.

Link to the job posting. 

You can get an idea of what goes on in this shop in this video of SDSS plate production

Miembros del SDSS Chileno Visitan APO – Chilean SDSS Members Visit APO

A post by Garrett Ebelke, Telescope Operation Specialist and APOGEE Hardware Development and Training Coordinator at Apache Point Observatory. Translated into Spanish by Loreto Barcos and Guillermo Damke (University of Virginia), with help from Veronica Motta (Universidad de Valparaíso, Chile).

Publicado por Garret Ebelke, Especialista de Operaciones del Telescopio y Coordinador de Desarrollo y Entrenamiento del Instrumento de APOGEE del Observatorio Apache Point. Traducido al Español por Loreto Barcos-Muñoz y Guillermo Damke (Universidad de Virginia, con ayuda de Veronica Motta (Universidad de Valparaíso, Chile).

Durante la segunda mitad de Abril, los ingenieros Daniel Garrido y Mario Cáceres viajaron desde Chile al Observatorio Apache Point (APO, por sus siglas en inglés), en Nuevo México, como parte del proyecto QUIMAL de la Universidad de La Serena. El objetivo de su viaje fue conocer en profundidad la infraestructura del instrumento de APOGEE para adquirir un conocimiento más acabado de sus numerosos subsistemas. Estos serán replicados en el proyecto APOGEE-2 e instalados en el telescopio du Pont de 2.5 m ubicado en el Observatorio Las Campanas (LCO, por sus siglas en inglés).

During the second half of April, Daniel Garrido and Mario Caceres, both engineers from Chile, travelled to Apache Point Observatory in New Mexico as part of the QUIMAL project at the Universidad de La Serena. The purpose of their trip was to delve deep into the APOGEE infrastructure hardware to gain a better understanding of the numerous hardware sub-systems. These systems will be replicated for the APOGEE-2 project and installed at the du Pont 100-inch Telescope at Las Campanas Observatory.

[For more on the plans for APOGEE observing at Las Campanas see this blog post.]

 

Daniel Garrido (left), Mario Caceres (right) at APO

Daniel Garrido (left), Mario Caceres (right) at APODaniel Garrido (a la izquierda) y Mario Cáceres (a la derecha) en APO.

While at APO, they were introduced to the daily task of plugging fiber optics into spectrographic plug plates, all contained within cartridges. They became very familiar with mounting these cartridges to the telescope, and how much care must be taken when handling the cartridges. A similar cartridge design will be used at LCO and Daniel will be heavily involved in assembling and populating the cartridges with fiber optics. Daniel was very eager to explore the internal configuration of the cartridges and quickly got his hands dirty once we opened a cartridge.

Durante su visita a APO, se les inició en la tarea diaria de conectar fibras ópticas a placas espectrográficas, cada una contenida en distintos cartuchos. Daniel y Mario también aprendieron a montar estos cartuchos en el telescopio y entendieron la delicadeza de este proceso. Los cartuchos que se utilizarán en el LCO tendrán un diseño similar. Daniel además estará involucrado en el montaje e instalación de las fibras ópticas en los cartuchos en el LCO. Daniel mostró mucho entusiasmo en explorar la configuración interna de los cartuchos y no tuvo inconvenientes en “ensuciarse las manos” para estudiarlos por sí mismo.

Mario and Daniel plugging fiber optics into a spectrograph plug plate

Mario y Daniel conectando las fibras ópticas en una placa espectrográfica. Mario and Daniel plugging fiber optics into a spectrograph plug plate.

Daniel pushes a cartridge to the telescope

Daniel pushes a cartridge to the telescope. Daniel empuja un cartucho hacia el telescopio.

Daniel (left), Mario (right) explore the internal configuration of an APOGEE fiber optic cartridge

Daniel (a la izquierda) y Mario (a la derecha) exploran la configuración interna de un cartucho de APOGEE. Daniel (left), Mario (right) explore the internal configuration of an APOGEE fiber optic cartridge.

No pudimos dejarlos marcharse de APO sin antes llevarlos a disfrutar del lado oscuro de las operaciones, donde pasaron varias noches familiarizándose con las operaciones nocturnas. Una parte importante de las observaciones es el aprendizaje del software usado para controlar el telescopio y el instrumento de APOGEE.

We couldn’t let them leave APO without letting them join the dark side of operations, where they spent several nights being introduced to nightly operations. A major part of observing is learning the software used to interface with the telescope and the APOGEE instrument.

Moses Marchante (SDSS Telescope Operations Specialist) introduces Daniel and Mario to the interface software used to control the telescope and the APOGEE instrument.

Moses Marchante (SDSS Telescope Operations Specialist) introduces Daniel and Mario to the interface software used to control the telescope and the APOGEE instrument. Moses Marchante, Especialista de Operaciones del Telescopio Sloan Digital Sky Survey (Relevamiento Digital del Cielo Sloan, SDSS por sus siglas en inglés), les enseña a Daniel y Mario el software de la interface usada para controlar el telescopio y el instrumento APOGEE.

This was an excellent start to incorporating some Chilean participants to the APOGEE-2 project, the hardware designs, operational processes and forge an excellent working relationship that will last throughout the entire project.

Esta fue una gran oportunidad para comenzar a incorporar participantes chilenos al proyecto APOGEE-2, al diseño del instrumento, los procesos operacionales, y para forjar una excelente relación de trabajo que durará a lo largo de todo el proyecto.

Daniel and Mario in front of the APOGEE instrument

Daniel y Mario frente al instrumento APOGEE. Daniel and Mario in front of the APOGEE instrument.

All photos were taken using Daniel Garrido’s camera, there are many more photos at Mario’s web gallery

MaNGA’s First Galaxies

A post by Anne-Marie Weijmans, the MaNGA Lead Observer: 

Last month MaNGA (Mapping Nearby Galaxies at APO) had its first commissioning run at Apache Point Observatory, with its first installed cartridge. MaNGA is part of SDSS-IV and scheduled to start observing in July of this year, but it now already has its first galaxies in hand!

MaNGA is an integral-field spectroscopy survey, which will map the motions and properties of stars and gas in 10,000 galaxies. By grouping fibers together into integral-field units, MaNGA obtains spectra not just of the centre of the galaxy, but also its outskirts, covering the whole galaxy. This means that we can measure properties of stars, such as age and metallicity, over a large surface area in the galaxy, and based on that, figure out how these galaxies were assembled. We also are able to measure the velocities of the stars, which in turn tells us about the structure of the galaxy, and how much dark matter is present. From the gas, we learn about the radiation present in the galaxy: is the gas energized by young stars (indicating that there is on-going star formation), by an active black hole, or both? Combining all these different sets of information, we form a picture of how different galaxies form, and evolve over time.

Niv and Nick installing the cartridge

MaNGA chief engineer Nick MacDonald (UW) and instrument scientist Niv Drory (UT at Austin) inspecting the first MaNGA cartridge, before mounting it to the telescope (credit: A. Weijmans).

MaNGA instrument scientist Niv Drory (UT at Austin) and chief engineer Nick MacDonald (UW) prepared the cartridge, carefully adding the MaNGA integral-field units and making sure that the surfaces of the fibers were clean to optimize their light throughput. The observers at APO, together with MaNGA lead observer Anne-Marie Weijmans and several other members of the MaNGA team took various test-observations of sky and stars, before turning their attention to galaxies. MaNGA can observe 17 galaxies in one go, and with two plates completed this resulted in 34 galaxies.

MaNGA Observing Team

The MaNGA observing team at APO. From left to right: David Law (Toronto), John Parejko (Yale), Niv Drory (UT at Austin), Nick MacDonald (UW), PI Kevin Bundy (IPMU), Anne-Marie Weijmans (St Andrews), Renbin Yan (Kentucky), Brian Cherinka (Toronto), José Sánchez-Gallego (Kentucky) and Hai Fu (Iowa). (credit: D.R. Law).

Right now, two more cartridges are being prepared for MaNGA to start observing this summer, and in the Fall, three more cartridges will follow. And at the same time, MaNGA lead data scientist David Law (Toronto) and survey scientist Renbin Yan (Kentucky) with many other members of the MaNGA team are working hard to analyze the results of these first 34 galaxies. Only 9,966 more to go!

MaNGA First Galaxies

One plate full of galaxies. These galaxies are the very first ones observed by the final MaNGA instrument. Some galaxies have been off-set from the centre of the IFU to allow inclusion of foreground stars, to test our measurement precisions. (credit: K. Bundy).

To keep in touch with MaNGA and see what we are up to, follow us on Twitter @MaNGASurvey.

A few more pictures:

 

 

MaNGA plate

MaNGA galaxy plate, showing the holes for the MaNGA IFUs and sky fibers (credit: D.R. Law)

Anne-Marie plugging a MaNGA plate

Attempt at plugging a MaNGA plate by lead observer Anne-Marie Weijmans (St Andrews), (credit N. Drory).

Stargazing

MaNGA observers watching the stars (credit: D.R. Law).

 

APOGEE2 Engineering Run at Las Campanas Observatory, Chile

The APOGEE-2 survey of SDSS-IV plans to run observations both at the Sloan 2.5m telescope at Apache Point Observatory, New Mexico, and at the du Pont 2.5m telescope at Las Campanas Observatory in Chile. This will enable observations from both hemispheres, allowing APOGEE-2 to efficiently obtain spectra of stars from all regions of our own Galaxy. Observations from Chile are due to start in 2016.

Last month, several members of the APOGEE-2 Team had three engineering nights kindly provided by the Carnegie Institution on the du Pont 100-inch Telescope. This time was needed for engineering work in preparation for use of the telescope with APOGEE. Paul Harding (Case Western), John Wilson (UVa), French Leger (UW), Garrett Ebelke (APO) and Fred Hearty (PSU) made nighttime measurements in the visual and near-infrared wavelengths to help determine the optimal focal plane location and radius of curvature for wide-field telescope use (ie. the best places to put the tips of the APOGEE fibers so they capture as much of the light from target stars as possible).

du Pont 2.5m

The 3-segment wide-field baffle system on the du Pont 2.5m telescope

Before the run the Las Campanas Observatory staff installed the 3-segment wide-field baffle system so the team could measure vignetting as a function of field location using both traditional and pinhole imaging. The 3-segment wide-field baffle system uses three different blackened, conical, tubes mounted between the telescope mirrors to ensure that only light from the direction the telescope is aimed reaches the focal plane. This was the first time the 3-segment baffle system had been installed in about 15 years.

French Leger

French Leger and the mechanical assembly he designed which allowed precise camera positioning in three dimensions at various locations behind the telescope.

 

Installation of the assembly

Installation of the assembly. In the foreground are Paul Harding (left) and Oscar Duhalde (right, a member of the Observatory Staff).

This run was an excellent first start to learning the wide-field capabilities of the du Pont telescope and how best to position the hundreds of fibers in the focal plane.  Another run is planned for late this year to make further measurements.

Video of SDSS Plate Drilling

Below is a video showing the production of SDSS plug plates in the Physics Instrument Shop at The University of Washington. Plates are drilled, cleaned, and measured here before being shipped to APO. Once installed on the SDSS 2.5m telescope at APO, optical fibers carry light from each hole to the spectrograph being used. Every plate represents a patch of sky three degrees in diameter. The SDSS spectrograph allowed for 640 targets in this region, with the BOSS spectrograph that increased to 1000.

Videography and Editing by Gaelen Sayres and Mary Kawamura.

Music: Williamson – Hello Mr. Hoshi.

With thanks to Connor Sayres for sending us the video.