Dark Energy Spectroscopic Instrument (DESI)

Hanyu Zhang

by

pfagrelius

What is your position or role in the DESI project?
I am a PhD student working with my supervisor Lado Samushia from Kansas state university mainly involved in Galaxy & quasar clustering working group.

Where were you born and where do you live now?
I was born in Beijing, spent my college time at Nanjing and now live in Manhattan, Kansas. Of course I feel most at home in Beijing but I am getting used to life in this peaceful and friendly small town in the Midwest.

What are the interesting places that standout that your work has taken you to?
Before starting graduate school, I got a chance to travel to Canary island, which is in the Atlantic Ocean, for a cosmology summer school. The night there is so dark and mysterious. I grew up in a big city and I have never seen such a clear but starry sky. I am looking forward to visiting Kitt Peak through a DESI related trip someday.

What would you say is the most interesting or exciting thing about your job?
As a DESI member, I have the opportunity to work with top groups from all over the world and it’s really exciting to see effort from collaboration members pushing the project forward. Personally, I enjoy extracting physics information for huge datasets. There are different ways to analyze DESI data and you can always find something new. It is interesting to gradually unveil the mystery of the universe.

Any advice for aspiring scientists?
Find your research interest, keep moving forward and learn coding.

Finally, what do you do for fun?
I used to play piano but I don’t have one here. I do photography, hiking and gaming. Dota2 will be a good topic but not League of Legends.

¿Cuál es tu posición en el proyecto DESI?
Soy estudiante de doctorado, trabajando con mi supervisor Lado Samushia, de la Universidad Estatal de Kansas, me involucro principalmente en el grupo de trabajo de aglomeración de galaxias y cuásares.

¿Dónde naciste y dónde vives ahora?
Nací en Beijing, viví durante la licenciatura en Nanjing, y ahora vivo en Manhattan, Kansas. Por supuesto que donde me siento más en casa es en Beijing, pero me estoy acostumbrando a la vida en este pacífico y amistoso pueblito del medio-oeste.

¿Cuáles son los lugares interesantes más destacados a donde te ha llevado tu trabajo?
Antes de empezar el posgrado tuve oportunidad de viajar a las Islas Canarias, en el Océano Atlántico, para una escuela de verano de cosmología. La noche ahí es tan oscura y misteriosa. Crecí en una ciudad grande y nunca había visto un cielo tan claro y estrellado. Estoy muy emocionada por visitar Kitt Peak en un viaje relacionado con DESI algún día.

¿Qué dirías que es lo más interesante y emocionante de tu trabajo?
Como miembro de DESI, tengo la oportunidad de trabajar con grupos de todo el mundo y es muy emocionante ver el esfuerzo de los miembros de la colaboración llevando al proyecto hacia adelante. Personalmente, disfruto extrayendo la física de grandes conjuntos de datos. Hay diferentes maneras de analizar los datos de DESI y siempre se encuentra algo nuevo, Es interesante develar poco a poco los misterios del Universo.

¿Algún consejo para aspirantes a científicos?
Encuentra tus intereses en la investigación, sigue adelante y aprende a escribir código.

Finalmente, ¿Qué haces para divertirte?
Solía tocar el piano, pero no tengo uno aquí. Hago fotografía y excursionismo. Me gustan los videojuegos,  “Dota2” es un buen tema pero no “League of Legends”.

¿Cuál es tu rol en el proyecto DESI?
Soy postdoc, y estoy involucrado principalmente en el grupo de trabajo de agrupamientos de galaxias y cuásares (Galaxy and Quasar Clustering, GQC)

¿Dónde naciste y dónde vives ahora? 
Nací en Seúl, Corea. Actualmente vivo en Shanghai, China, donde tengo una posición postdoctoral en SJTU ( Universidad Jiao Tong)

¿Qué dirías que es lo más interesante o emocionante de tu trabajo?
Para mi, una de las cosas más interesantes de DESI es la experiencia en el procesamiento de datos espectroscópicos. Antes de unirme a  DESI, para mi los “datos” eran simplemente un conjunto de archivos en formato binario, que consistían en muchas columnas que incluyen la ascensión recta, declinación, desplazamiento al rojo y algunos pesos. Ahora, estando en DESI, he tenido muchas oportunidades de aprender como los datos crudos son procesados en los flujos de análisis que producen los archivos que antes solo llegaban a mis manos. Por ejemplo, participando en la inspección visual de espectros, y trabajando con el código de asignación de fibras

¿Algún consejo para aspirantes a científicos?
Tanto los éxitos como los fracasos, pueden ser escalones para dar el siguiente paso.

Finalmente, ¿Qué haces para divertirte?
Leo libros. Prefiero leerlos lentamente y disfrutar cada línea, que leerlos rápido, lo que me hace sentir que estoy teniendo una conversación con el autor. Recientemente ( no sabría decir si debido a, ó  gracias a, la COVID19, pero da igual) inicié un par de clubs de lectura en línea, con algunos viejos amigos. Después de leer un capítulo del mismo libro, cada una o dos semanas, nos reunimos en línea y discutimos sobre cualquier cosa relacionada con el capítulo. Quizá quieras intentarlo, ¡es realmente divertido!

 

 

 

What is your role in the DESI project?
I’m a post-doc mainly involved in GQC working group.

Where were you born? Where do you live now? 
I was born in Seoul, Korea and currently living in Shanghai, China for my post-doc position at SJTU.

What would you say is the most interesting or exciting thing about DESI?
One of the most interesting thing about DESI for me is to experience the pipeline for processing spectroscopic data. Before joining DESI, ‘data’ were just some binary files to me consisting of many columns including RA, DEC, z, and some weights. But, after joining DESI, I had many chances to learn about how raw data are processed in the pipelines before arriving at my hands. For example, participating in visual inspection and working on fiber assignment are the ones where I can experience some part of the raw data process.

Any advice for aspiring scientists?
Either failure or success, it can be a stepping stone for the next step.

Finally, what do you do for fun?
Reading books. Rather than reading fast, I prefer slow reading and enjoying each line, which makes me feel like having conversation with author. And, recently, (I’m not sure if I should say “because of“ or “thanks to” COVID19, but anyway) I started a couple of online book clubs with some old friends. After reading one chapter of the same book every week or every two weeks, we regularly meet online and discuss anything related to the chapter. You may want to try this as well. It is really fun!

By: Aaron Meisner
November 17, 2020

It’s remarkable to think that our DESI Legacy Surveys team completed on order a thousand nights of ground-based observing from Kitt Peak and Cerro Tololo. All the while in low-Earth orbit, NASA’s WISE satellite has been steadily and reliably amassing nearly a decade of full-sky data at infrared wavelengths of 3-5 microns. WISE continuously obtains a new pair of degree-sized images every ~10 seconds, observing around the clock.

Selection of DESI’s luminous red galaxy and quasar targets requires not only optical data from telescopes like the Mayall and Blanco, but also infrared fluxes from WISE. It’s therefore crucial that DESI target selection make full use of the entire WISE data set. Once each year, we download millions of recently acquired raw WISE images to NERSC and use these to update DESI’s custom, coadded WISE maps. As of DR9, the raw WISE data set assembled at NERSC has grown to a quarter petabyte in size! Each year, upon completion of our latest WISE map-making efforts, we can once again declare that DESI has created the deepest ever full-sky maps and catalogs at mid-infrared wavelengths. DR9 incorporates seven years of WISE observations, versus five years for DR8 and just one year for DR1.

WISE has scanned the entire sky more than a dozen times, lending a strong time-domain component to the Legacy Surveys data products. Our Legacy Surveys WISE light curves for ~2 billion sources represent a totally unprecedented and as-yet little explored data set. Mining DR9’s infrared data products, especially in combination with optical Legacy Surveys photometry and DESI spectroscopy, will provide a diverse array of scientific opportunities throughout the coming years.

 

Light echoes from a Milky Way supernova, as seen in the time-domain ‘unWISE’ coadds of Legacy Surveys DR9. These custom WISE coadds also enable DESI’s selection of faint variable quasar candidates.

The Kitt Peak National Observatory, where the Mayall telescope houses the Dark Energy Spectroscopic Instrument, was closed in March, 2020 due to the global coronavirus pandemic. The observatory cautiously and carefully reopened for maintenance in September, 2020 and since then has been slowly ramping up activities. Critical telescope maintenance and instrument improvements are being made in anticipation of a re-commissioning phase of DESI in November. Following this re-commissioning period, during which we will confirm that the instrument provides the same performance as it did pre-shutdown, we will start our Survey Validation phase. The team is excited and eager to once again start collecting data!

Matt Evatt and Patrick Dunlop practicing social distancing while preparing the Mayall telescope for on-sky DESI operations.

 

 

 

By: Adam Myers
November 4, 2020

The Dark Energy Spectroscopic Instrument will conduct spectroscopy of truly vast numbers of cosmological and astrophysical sources. These include Bright Galaxies, Emission Line Galaxies (ELGs), Luminous Red Galaxies (LRGs), Quasars, and objects in our own Milky Way Galaxy. DESI spectra are obtained by aligning optical fibers with locations on the sky, to collect light to be analyzed by dedicated spectrographs. But, how do DESI scientists know where to place those optical fibers in the first place?

Sources for the DESI key projects are targeted using images of the sky from the DESI Legacy Imaging Surveys. The Legacy Surveys include optical photometry from dedicated campaigns with the Mayall and Bok telescopes at Kitt Peak National Observatory, near Tucson, and the Blanco telescope at Cerro Tololo Inter-American Observatory near La Serena in Chile. The Legacy Surveys also incorporate infrared imaging from the WISE and NEOWISE missions, and source detections from the Gaia survey.

When envisioning the process of finding distinct objects in the sky, it is tempting to picture a bright, extended galaxy, such as this one:

Image from the Legacy Survey Viewer, using data from DR8 at right ascension of ~217.6 deg. and declination of ~11.9. See original here. credit: Legacy Surveys / D. Lang (Perimeter Institute)

But, in truth, the vast majority of DESI targets are far less spectacular to the eye, and are selected based on properties such as their color in addition to their shape. Below is the same image from the Legacy Survey Viewer above with the targets identified with circles.  You’ll see that there are many more DESI targets in this field than you might have naively expected!

Same image as above from the Legacy Survey Viewer with the targets identified. You can do this yourself by selecting “DESI Targets” in the Legacy Survey Viewer menu. credit: Legacy Surveys / D. Lang (Perimeter Institute)

To determine which of the one-and-a-half-billion or so sources in the Legacy Surveys will be the lucky few tens-of-millions targeted by DESI requires sophisticated computer algorithms to sift through sources and target objects with specific photometric properties. The publicly available software that DESI uses, which is called desitarget, comprises tens-of-thousands of lines of code and has received contributions from dozens of DESI scientists.

The DESI collaboration recently released a series of research notes detailing the currently expected targeting algorithms for the DESI five-year survey:

The target catalogs that correspond to these notes, which are drawn from Data Release 8 of the DESI Legacy Imaging Surveys, are publicly available here in a format described here.

Although it is a significant milestone to have the first official DESI target catalogs in-hand, the dedicated effort of the collaboration continues. The next data release of the Legacy Surveys (Data Release 9) will soon be used to optimize, refine and finalize the target catalogs for the DESI five-year survey, during a phase of the project known as Survey Validation.

¿Cuál es tu posición o rol en el proyecto DESI?
Soy estudiante de doctorado y contribuyo principalmente a los grupos de trabajo de selección de objetivos y Física de cuásares y galaxias.

¿Dónde naciste y dónde vives actualmente?
Nací en un pueblito en el noreste de la India, llamado Agartala. Después de hacer mis estudios de pregrado en Bhubaneswar, India, me mudé a Pittsburgh, EUA, donde estoy haciendo mis estudios de posgrado en la Universidad de Pittsburgh.

¿Qué haces como parte de DESI?
Trabajo principalmente en el desarrollo y prueba de algoritmos para seleccionar los objetos de los que DESI va a medir espectros usando datos de los sondeos de imagen. Después de las observaciones, hago una revisión de los espectros para confirmar que los datos satisfacen los requisitos científicos. También trabajo estudiando la física de galaxias, y quiero estudiar la evolución de las poblaciones galácticas. También he observado con el instrumento y he ayudado al desarrollo de la infraestructura del censo.

¿Qué es lo más interesante o emocionante de DESI (y/o tu trabajo y/o la Astronomía en general)?
La astronomía es la forma más antigua de ciencia observacional, pero aún sabemos muy poco sobre nuestro universo. ¡Aún no sabemos de qué está hecho el 95% del universo! Siendo parte de DESI puedo trabajar con muchas personas maravillosas que intentan responder algunas de las preguntas más básicas y profundas sobre el Universo, como: ¿cuándo y por qué empezó todo? ¿qué es lo que causa la expansión del Universo? Esta exploración de lo desconocido es lo que más me emociona.

¿Algún consejo para alguien que aspire a ser científico?
Sé curioso, haz preguntas e intenta explorar todos los recursos disponibles para responderte tú mismo. A veces encontrarás las respuestas, a veces no, pero en el proceso llegarás a entender el método científico de dar seguimiento a un problema. Aún si no acabas siendo un científico profesional, creo que aprender el método científico para resolver cualquier problema de la vida es muy importante.

¿Qué haces para divertirte/en tus tiempos libres?
Amo explorar diferentes gastronomías y recrearlas por mí mismo. Amo las caminatas y explorar nuevos lugares. También me gusta mucho hablar con otras personas sobre ciencia y ayudar a organizar eventos de divulgación científica en la ciudad.


What is your position or role in the DESI project?
I am a PhD student working mainly as a part of the Target Selection and Galaxy and Quasar Physics Working Groups.

Where were you born and where do you live now?
I was born in a small town in North Eastern India called Agartala. After doing by undergraduate studies in Bhubaneswar, India, I moved to Pittsburgh, USA where I am currently doing my grad school at the University of Pittsburgh.

What do you do as part of DESI?
I mostly work on developing and testing algorithms to select objects of which DESI will measure the spectra using the data from the imaging surveys. After the observations, I also go through the spectra to check whether the data satisfies all the science requirements. I also work on studying the physics of galaxies and want to study how populations of galaxies evolve. I have also done some observations with the instrument and help in developing some of the infrastructure for the survey.

What is the most interesting or exciting thing about DESI ?
Astronomy is the oldest form of observational science but we still know so little about our universe. We are still in the dark about what 95% of the universe is made of! By being a part of DESI, I get to work with a lot of wonderful people who are trying to answer some of the most basic and profound questions about our Universe like, When and Why did everything begin? or What is causing the expansion of the Universe? This exploration of the unknown is what excites me the most.

Any advice for an aspiring scientist?
Be curious, ask questions and try explore all the resources available to find the answers yourself. Sometimes you will find an answer, sometimes you won’t but in the process you will get to understand the scientific method of tackling a problem. Even if you don’t end up being a professional scientist, I believe learning the scientific method to solve any problem in our life is very important.

What do you do for fun? 
​I love exploring different cuisines and and recreate them on my own. I love to go out on hikes and explore new places. I also like to talk to others about science and help organize science outreach events in the city.

¿Cuál es tu rol en DESI?
Soy investigador en el  LLNL (Laboratorio Nacional Lawrence Livermore) y trabajo en el equipo de operaciones de DESI.

¿Dónde naciste?
Nací en St. Louis, Missouri.

¿Dónde vives ahora?
Vivo en San Leandro, California, justo al sur de Oakland.

¿Qué actividades realizas en DESI?
Recientemente me he enfocado en comprobar la precisión del posicionamiento de las fibras, y finalizar el sondeo de imágenes. También trabajo en la programación de observación del telescopio. Mi trabajo se relaciona completamente con software, así que en el día a día escribo código y hago gráficas. Finalmente, pienso mucho en cómo los errores sistemáticos en los sondeos de imágenes pueden imprimirse en los mapas que haremos con DESI.

¿Qué dirías que es lo más interesante o emocionante al respecto de DESI?
La escala de los proyectos en los que estamos trabajando es simplemente increíble, en varios sentidos:

  • El mapa más grande del universo
  • El mapa más grande de la Vía Láctea
  • Millones de espectros, miles de fibras, decenas de espectrógrafos.

Es emocionante ver cómo todo esto se une.

¿Algún consejo para aspirantes a científicos?
¡Aprende a programar! Hay un montón de cosas interesantes a la espera de ser encontradas en datos científicos reales y hoy puedes encontrarlas desde casa usando sólo una computadora.

¿Qué haces para divertirte?
Recientemente paso mucho tiempo construyendo estructuras y leyendo a mi hijo de dos años. También voy de excursión, juego frisbee y leo para mí mismo.

What is your position or role in the DESI project?
I’m a researcher at LLNL working on the DESI operations team.

Where were you born? 
I was born in St. Louis, MO.

Where do you live now?
I live in San Leandro, CA, just south of Oakland.

What do you as part of DESI? 
My recent focus has been on testing the accuracy of the fiber positioning and finishing the imaging survey.  I also work on the telescope scheduling.  My work is entirely on the software side, so on a day-to-day basis I write code and make plots.  Finally, I think a lot about how systematics in the imaging can imprint onto the maps we’ll make with DESI.

What is the most interesting or exciting thing about DESI?
The scale of the projects we’re working on is just awesome, in a number of senses:

  • largest map of the universe
  • largest map of the Milky Way
  • millions of spectra, thousands of fibers, tens of spectrographs

It is thrilling to see all of this come together.

Any advice for an aspiring scientist?
Learn to program!  There is a ton of interesting stuff waiting to be found in real scientific data, and you can find it from home today using just a computer.

What do you do for fun? 
Recently, I spend a lot of time building structures with and reading to my two-year-old son.  I also hike, play frisbee, and read to myself.

¿Cuál es tu rol en DESI?
Soy parte del equipo que desarrolló los GFA. Personalmente implementé el firmware que se ejecuta en los GFA, y participé en algunas partes del software, así como en algunas tareas de administración. [Nota: El GFA es la cámara de guía, enfoque y alineación en el plano focal.]

¿Dónde naciste?
En Barcelona, España.

¿Dónde vives ahora?
En una pequeña ciudad llamada Terrassa, cerca de Barcelona.

¿Qué actividades realizas en DESI?
Los GFA son controladores CCD con un pequeño factor de forma utilizado en la Guía, Enfoque y Alineación en DESI. Fueron completamente diseñados y desarrollados en el IFAE en Barcelona. Ahora, estamos enfocados en la búsqueda de errores y en resolver algunos problemas que se detectaron durante la puesta en marcha de DESI.

¿Qué dirías que es lo más interesante o emocionante al respecto de DESI?
Siempre me ha apasionado la ciencia y la tecnología. Esto me llevó a obtener un título en Física y otro en Ingeniería Electrónica. Trabajar en DESI, así como en otros proyectos en los que colaboro en mi instituto, me permite aplicar mis habilidades técnicas en proyectos de Física, en los cuales puedo disfrutar de las dos partes del proyecto: la ciencia y la ingeniería. Además, me da la oportunidad de viajar a lugares maravillosos, con asombrosos instrumentos de investigación, y conocer gente muy interesante.

¿Algún consejo para un aspirante a científico?
Supongo que esto no va a sonar original, pero le diría que trabaje duro, que sea apasionado y que no tenga miedo de asumir responsabilidades.

¿Qué haces para divertirte?
Soy fotógrafo aficionado, y siempre estoy pensando en apps, o dispositivos electrónicos que pueda construir.

What is your position or role in the DESI project?
I am part of the team that developed the GFA units. I personally implemented the firmware running on the GFA and participated in the software parts, as well as some management tasks. [Note: The GFA is the Guide, Focus and Alignment camera on the focal plate]

Where were you born?
I was born in Barcelona, Spain.

Where do you live now?
In a small city near Barcelona called Terrassa.

What do you as part of DESI?
The GFAs are a small form factor CCD controller used in Guiding, Focus, and Alignment in DESI. It was completely designed and developed at IFAE in Barcelona. Now we are mainly doing bug hunting and solving some problems that were detected during the DESI commissioning.

What is the most interesting or exciting thing about DESI?
I’ve always been passionate about science and technology. This led me to get a degree in Physics and another one in Electronic Engineering. Working in DESI as well as in other projects where I collaborate in my institute lets me apply my technical skills in Physics projects, so I can enjoy both sides of the projects, science and engineering. Also, it gives me the opportunity to travel to amazing places with amazing  research instruments and meet very interesting people.

Any advice for an aspiring scientist?
I guess I won’t be original, but I will go with, work hard, be passionate, and do not be afraid of taking responsibilities.

What do you do for fun?
I am an amateur photographer and I am always thinking about apps or electronic devices I could make.

 

¿Cuál es tu posición o rol en el proyecto DESI?
Soy estudiante de doctorado, y trabajo en simulaciones para el grupo del bosque de Lyman-alpha.

¿Dónde naciste?
Nací en la Ciudad de México, México

¿Dónde vives actualmente?
Vivo en la Ciudad de México, México.

¿Qué haces como parte de DESI?
Trabajo cambiando la composición química del medio intergaláctico para las simulaciones del bosque de Ly-alpha. He observado en el telescopio Mayall y recientemente me he involucrado en el grupo de Divulgación y en las redes de los “Científicos de carrera temprana”

¿Qué es lo más interesante o emocionante de DESI?
Lo más emocionante de la Astronomía es el hecho de que de un lugar minúsculo en el Universo podamos conocer tanto (¡Y a la vez tan poco!) sobre él, su estructura y su evolución. Sobre mi trabajo, ver cómo cambia el universo virtual que “creamos” cuando hago cambios en las simulaciones. Sobre DESI, disfruto mucho mi trabajo diario, pero la mejor parte es pasar unos días trabajando en el telescopio y con el instrumento. Dentro de la colaboración, es muy emocionante trabajar y compartir con astrónomos y cosmólogos a quienes admiro, y conocer a los seres humanos detrás de los artículos con los que trabajo cotidianamente.

¿Algún consejo para alguien que aspire a ser científico?
No importa cuán difícil parezca el camino, no rendirse del sueño de lograr ser quien desean ser. Permitirse convertirse en el adulto que deseaban ser cuando eran niños, y que ese niño se sienta orgulloso de ustedes: ¡nunca dejen de cuestionarse!

¿Qué haces para divertirte/en tus tiempos libres?
Soy una bailarina que intenta encontrar su propio idioma y tomo clases de diferentes géneros. Amo viajar, hago fotografía, soy una apasionada de la espiritualidad; medito, pinto (aunque no soy muy buena), hago jardinería, paso tiempo con mis mascotas y cocino – y por supuesto, lo que todos hacemos: veo películas y series, y pierdo el tiempo en redes sociales.

 

What is your position or role in the DESI project?
I am a PhD student working on simulations for the Lyman-alpha working group

Where were you born? 
I was born in Mexico City, Mexico

Where do you live now?
I am currently living in Mexico City, Mexico

What do you as part of DESI?
I work changing the chemical composition of the Intergalactic Medium for the Lya-forest simulations, I have observed at the Mayall, and I just started to get more involved in Public Outreach and with the Early Career Scientists’ network.

What is the most interesting or exciting thing about DESI?
The most exciting thing of Astronomy for me is how from a very small place in the Universe we are able to know so much (and still so little!) about the Universe, its structure and evolution.  About my job, to see how the changes I make on the simulations affect the virtual universe we “create”. About DESI, I enjoy my daily work a lot, but the best part is getting to spend a few days working with the telescope and the instrument. Within the collaboration, it is also very exciting to know and share with astronomers and cosmologists who I admire, and getting to know the human beings behind the papers I read for my work.

Any advice for an aspiring scientist?
No matter how hard the way looks, don’t give up on the dream of becoming who you want to be. Allow yourself to turn into the grownup you wished to be when you were a child, and make that child proud: never stop questioning!

What do you do for fun?
I am a dancer trying to find her own language, so I currently take lessons of different styles. I love to travel, I do photography, I am passionate about spirituality, I meditate, paint (I’m not very skilled though), garden, spend time with my pets, and cook – and of course what most people do: watch movies and shows, and waste time in social media.

What is your position or role in the DESI project?

I’m a theoretical cosmologist, who also has a lot of expertise in redshift surveys through the WiggleZ Dark Energy Survey and the Australian Dark Energy Survey (OzDES) on the Anglo-Australian Telescope.  At the moment I’m helping lead the visual inspection of survey validation data, focussing on quasars.  I am also helping out on the DESI membership committee and external collaborator committee.

Where were you born?

I was born in Sydney, Australia.

Where do you live now?<

I now live in Brisbane, Australia.

What do you as part of DESI? 

At the moment I am spending a lot of time looking at some of the first spectra to come through the DESI instrument.  We are making sure the spectra are of high quality (they’re amazing!) and that our analysis software is giving the correct results for the redshift of each object we look at.

At the same time I’m still working on cosmology theory, and seeing how our data can best test theories of dark energy and dark matter that go beyond our standard cosmological model.

What is the most interesting or exciting thing about DESI?

I think one of the coolest things DESI will do is measure the mass of neutrinos.  When starting out in cosmology I never thought that making the largest ever map of the distribution of galaxies in the universe would help us understand the properties of one of the most enigmatic particles in the standard model of particle physics.  But the neutrino mass has an impact on the formation and growth of structure in the early universe, so we can detect its effects with DESI.  Feels to me like a great demonstration of the fundamental interconnectedness of all things (to borrow a Douglas Adams quote).

Any advice for an aspiring scientist?

Enjoy it.  It’s a privilege to be able to do research.  It’s an amazing career.  However, I see many junior researchers stressing over their future, when they really don’t need to!  There are so many great things you can do with the experience you gain from a PhD, and your skills will be in high demand in all sorts of industries.  My trick to stay relaxed and happy in research is this: don’t go into it expecting to do it forever, and don’t stress about whether you’ll get your next job in research or not… just be appreciative of the time you do get to do it.  Funnily enough if you use that technique, you may just find yourself succeeding beyond your wildest dreams!  I once asked my PhD supervisor if I was doing okay in my PhD.  He asked me “Are you enjoying it?”  I responded, “Yes.”  So he said, “Then you’re doing it right.”

There’s lots of other advice I could give, but that’s my main one.

What do you do for fun? 

My main fun-time thing to do is play Ultimate frisbee.  I’ve played all sorts of sports over my life, but Ultimate is the one that has occupied me since my PhD.  I have played all around the world, and represented Australia at seven world championships.  I love it, and the people-skills, leadership, and resilience I learnt from playing sport has definitely helped me in my career as an astrophysicist.

What is your position or role in the DESI project?

I am a core member of the Data Systems team, the group which is responsible for taking the “raw” observations from DESI and delivering science-ready data for the rest of the collaboration. I am also
actively involved in the DESI imaging surveys (check out legacysurvey.org/viewer to tour around the sky!), and the group which is responsible for choosing the targets that DESI will observe.

Where were you born?

I was born in Athens, Greece to a Greek father and an American mother, but moved to San Diego, California when I was eight years old. I grew up, as my father would say, a “beach bum!”

Where do you live now?

My family—my wife and two boys, aged 8 and 12—and I live near Albany, New York, about three hours north of New York City, where I am a physics professor at Siena College, a small private liberal arts college. We own a nice home on about half an acre, have a great dog, and raise chickens!

What do you do as part of DESI?

I spend between 20%-40% of my time on DESI, depending on how busy I am with teaching! Most of my time right now is spent in support of the imaging surveys, making sure that DESI will turn its powerful spectroscopic fibers on the “right” distant galaxies and quasars, which will tell us about the energy content and evolution of the universe.

What is the most interesting or exciting thing about DESI?

DESI is an incredibly ambitious and powerful instrument and project, which is tackling one of the most important outstanding problems in physics and arguably all of science—what is the physical nature of dark energy? The answer to this question will lead to new discoveries beyond our current knowledge, which is very exciting! It’s also a privilege to be working with such a bright and dedicated group of engineers and scientists. Tackling questions at the frontier of knowledge is what originally drew me to astronomy, and it’s humbling to be involved in the next 5-8 years of cutting-edge discoveries.

Any advice for an aspiring scientist?

My advice for an aspiring scientist is three-fold: First, be passionate about what you do; be curious, open to new ideas and perspectives, and strive to learn as much as you can at all times. Second, learn to code! Of course you should learn as much physics, astronomy, and math as you can, but I have found that being proficient with a programming language is enormously powerful and useful. And finally, learn to write well. The key to science is being able to communicate clearly and effectively.

What do you do for fun?

Most of my fun, free-time is spent with my family. I coach all my kid’s sports teams, including my younger son’s travel baseball team. I also love gardening, tackling “do-it-yourself” projects around the house, and exercising!

On May 8, 2020, the DOE Energy Systems Acquisition Advisory Board (ESAAB) approved the CD-4 completion of construction for the DESI Project. It’s the culmination of 10 years of hard work by an incredibly dedicated and talented team and a major accomplishment for all involved. DESI is now the premier multi-object spectrograph and the first stage-IV dark energy experiment to go on-sky.