UTexas: Upgraded Hobby-Eberly Telescope Dedicated

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UTexas: Upgraded Hobby-Eberly Telescope Dedicated

Postby bystander » Tue Apr 11, 2017 4:35 pm

Upgraded Hobby-Eberly Telescope Dedicated April 9
MacDonald Observatory | University of Texas | 2017 Apr 09

Dark energy survey, other cutting-edge science on the way

The world’s third-largest telescope, the 10-meter Hobby-Eberly Telescope (HET) located at McDonald Observatory in West Texas, has completed a multiyear $40 million upgrade to enable it to take on the biggest challenges in astronomy today: unraveling the mystery of dark energy, probing distant galaxies and black holes, discovering and characterizing planets around other stars and much more. ...

HET’s upgrade included a variety of aspects. The telescope’s field of view has been expanded to 70 percent of the diameter of the full Moon and now views an area of sky 120 times larger than before. And HET now sports an innovative new set of optics. “The Harold C. Simmons Dark Energy Optical System is one of the most complex optical systems ever deployed in astronomy,” said McDonald Observatory Director Dr. Taft Armandroff of The University of Texas at Austin. The Simmons System rides on the telescope’s new tracker, or “top end,” which enables tracking and guiding on cosmic targets.

A practically new telescope deserves a new set of instruments to make the most of its capabilities. Astronomers and engineers have built a suite of four instruments, each optimized for a different kind of research, for the new HET. (See appendix for details.)

The upgrade is an integral part of the upcoming Hobby-Eberly Telescope Dark Energy Experiment (HETDEX), a four-year project starting later this year that will study dark energy, the mysterious force causing the universe’s rate of expansion to speed up. This survey will look back 11 billion years and determine if dark energy has changed over time. ...
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Re: UTexas: Upgraded Hobby-Eberly Telescope Dedicated

Postby BDanielMayfield » Tue Apr 11, 2017 5:41 pm

Excellent!

My wife and I toured McDonald Observatory several years ago during a vacation to west Texas. The tour included a talk given inside the HET in a visitors room where we could see some of the scope's inner workings. It was a wonderful highlight of a great trip.

Though it is a 10 meter world class telescope, it was built as economically as possible, so at first it wasn't equipped with the range of motion that most telescopes have. Since its field of view was limited it relied more than most scopes on the daily and seasonal movements of the Earth to bring its targets into view. It's great to read of this upgrade so that it now can see much more of the sky on any given night and throughout each year.

There is one thing about the HET that makes it less well known though; it can't take pretty pictures because it is a dedicated spectrograph. It only spreads the light out from the objects it studies. This makes it a great scientific workhorse, telling us all kinds of things about what it studies, but no APODs (afaik) for the HET. It is often used and mentioned in the production of new science findings. This upgrade will continue and extend its functions.

Bruce

P.S. request, can at least a little more attention be directed via APODs toward this great instrument? It deserves it.
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Re: UTexas: Upgraded Hobby-Eberly Telescope Dedicated

Postby BDanielMayfield » Wed Apr 12, 2017 10:19 pm

A search of the archives revealed that the Hobby-Eberly has been featured on an APOD, but it was over 20 years ago on December 27, 1996 in an APOD entitled HET: The New Largest Optical Telescope. It's a grainy low quality construction photo, but the explanation was good.

But no APOD love since then? It's still the largest optical telescope on the North American continent. Info about the HET, the rest of McDonald Obseratory and the nearby annual Texas Star Party would make a great APOD & explanation.

Bruce
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BH's are just bigger when measured in Texas

Postby neufer » Thu Apr 13, 2017 4:08 am

https://en.wikipedia.org/wiki/NGC_1277 wrote:
<<NGC 1277 is a lenticular galaxy in the constellation of Perseus. It is a member of the Perseus Cluster of galaxies and is located approximately 220 million light years from the Milky Way. It has an apparent magnitude of 14.7. It was discovered on December 4, 1875 by Lawrence Parsons, 4th Earl of Rosse.

NGC 1277 has been called a "relic of the early universe" due to its stars being formed during a 100 million year interval about 12 billion years ago. Stars were formed at a rate of 1000 times that of the Milky Way galaxy's formation rate in a short burst of time. Then this generation process shut off leaving NGC 1277 populated with metal-rich stars about 7 billion years older than our Sun.

Observations made using the Hobby-Eberly Telescope at Texas's McDonald Observatory, suggested the presence of a black hole with a mass of about 17 billion solar masses, equivalent to 14% of the total stellar mass of the galaxy due to the motions of the stars near the center of the galaxy. This makes the black hole in NGC 1277 one of the largest known, in relation to the mass of its host galaxy.
'
viewtopic.php?f=31&t=30277&p=188605#p188474

A follow up study, based on the same data and published the following year, reached a very different conclusion. The black hole was estimated to be between 2 and 5 billion solar masses. This is about less than a third of the previously estimated mass which is significantly lower. Models with no black hole at all were found to provide reasonably good fits to the data, including the central region. More recently a group made observations using the Keck I Telescope and a black hole with mass 1.2×109 M fit the models the best.>>
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Re: BH's are just bigger when measured in Texas

Postby Ann » Thu Apr 13, 2017 5:47 am

neufer wrote:
https://en.wikipedia.org/wiki/NGC_1277 wrote:
<<NGC 1277 is a lenticular galaxy in the constellation of Perseus. It is a member of the Perseus Cluster of galaxies and is located approximately 220 million light years from the Milky Way. It has an apparent magnitude of 14.7. It was discovered on December 4, 1875 by Lawrence Parsons, 4th Earl of Rosse.

NGC 1277 has been called a "relic of the early universe" due to its stars being formed during a 100 million year interval about 12 billion years ago. Stars were formed at a rate of 1000 times that of the Milky Way galaxy's formation rate in a short burst of time. Then this generation process shut off leaving NGC 1277 populated with metal-rich stars about 7 billion years older than our Sun.

Observations made using the Hobby-Eberly Telescope at Texas's McDonald Observatory, suggested the presence of a black hole with a mass of about 17 billion solar masses, equivalent to 14% of the total stellar mass of the galaxy due to the motions of the stars near the center of the galaxy. This makes the black hole in NGC 1277 one of the largest known, in relation to the mass of its host galaxy.
'
viewtopic.php?f=31&t=30277&p=188605#p188474

A follow up study, based on the same data and published the following year, reached a very different conclusion. The black hole was estimated to be between 2 and 5 billion solar masses. This is about less than a third of the previously estimated mass which is significantly lower. Models with no black hole at all were found to provide reasonably good fits to the data, including the central region. More recently a group made observations using the Keck I Telescope and a black hole with mass 1.2×109 M fit the models the best.>>


In Swedish, "bh" means "breast holder", or bra. ("Bra" in Swedish means "good".)

The suggestion that BH's are bigger when measured in Texas puts some interesting pictures in my mind.


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Re: UTexas: Upgraded Hobby-Eberly Telescope Dedicated

Postby BDanielMayfield » Thu Apr 13, 2017 10:35 am

Sigh. "Don't bring me down" Art.

Was that apparent overestimate the 'scopes fault, or of the (mostly German) astronomers who where using it? What kind of crazy fine resolution would it take to accurately measure the Doppler velocities of stars in very close orbits around a SMBH in a galaxy that's 220 million lys away? It looks to this non professional like they where trying to stretch the limits of what the HET is capable of doing. An extraordinary claim rightly called for a review of the data, which corrected a faulty interpretation.

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Re: UTexas: Upgraded Hobby-Eberly Telescope Dedicated

Postby neufer » Thu Apr 13, 2017 1:10 pm

Ann wrote:
In Swedish, "bh" means "breast holder", or bra. ("Bra" in Swedish means "good".)

The suggestion that BH's are bigger when measured in Texas puts some interesting pictures in my mind.
BDanielMayfield wrote:
Sigh. "Don't bring me down" Art.

Was that apparent overestimate the 'scopes fault, or of the (mostly German) astronomers who where using it?

Remco C. E. van den Bosch, Karl Gebhardt, Kayhan Gültekin, Glenn van de Ven, Arjen van der Wel & Jonelle L. Walsh.

    "Van" is mostly Dutch , isn't it? (As in Ludwig van Beethoven.)
BDanielMayfield wrote:
What kind of crazy fine resolution would it take to accurately measure the Doppler velocities of stars in very close orbits around a SMBH in a galaxy that's 220 million lys away? It looks to this non professional like they where trying to stretch the limits of what the HET is capable of doing. An extraordinary claim rightly called for a review of the data, which corrected a faulty interpretation.

Emsellem's new expansion model produced a surprisingly good fit with a "bh" of just 2 billion masses
    (or possibly no "bh" at all):
https://academic.oup.com/mnras/article- ... ras/stt840 wrote:
Is the black hole in NGC 1277 really overmassive?
Eric Emsellem
Mon Not R Astron Soc (2013) 433 (3): 1862-1870.
DOI: https://doi.org/10.1093/mnras/stt840
Published: 20 June 2013

Abstract

<<A recent claim has been made by van den Bosch et al. that the fast-rotator galaxy NGC 1277 hosts an overmassive black hole with a mass (1.7 × 1010 M) larger than half its (central) stellar spheroid mass. We revisit this claim here by examining the predictions from simple dynamical realizations based on new multi-Gaussian expansion (MGE) models of NGC 1277, using the same inclination i = 75°, and constant mass-to-light ratios. We present realizations which fit well the observed photometry taking into account an approximation for the extinction due to the central dust ring. The mass-to-light ratio M/L is fixed following scaling relations which predict a Salpeter-like initial mass function for such a luminous early-type fast rotator, 60 per cent higher than the one of the previously derived best-fitting model. A model without a black hole provides a surprisingly good fit of the observed kinematics outside the unresolved central region, but not, as expected, of the central dispersion and Gauss–Hermite h4 values. A model with a black hole mass of 5 × 109 M allows us to fit the central dispersion profile, consistently with models of the same mass and M/L in van den Bosch et al. It departs from the central h4 values by only about twice the given uncertainty. A slightly varying M/L or the addition of high-velocity stars in the central spatially unresolved region would further lower the need for a very massive black hole in the central region of NGC 1277. These results do not, by themselves, rule out the presence of a presumed overmassive black hole at the centre of NGC 1277. However, they lead us to advocate the use of 3σ (as opposed to 1σ) confidence intervals for derived MBH as better, more conservative, guidelines for such studies. We also caution for the use of ill-defined spheroidal components as an input for scaling relations, and emphasize the fact that a MBH in the range 2–5 × 109 M would represent less than 5 per cent of the spheroid bulge-like mass of our models and less than 2.5 per cent of its total stellar mass. This would make the black hole in NGC 1277 consistent or just twice as large as what a recent version of the MBH–σ predicts, well within the observed scatter. We examine the impact of the presence of an inner bar by running simulations from the same MGE model but with extreme anisotropies. An inner small (600 pc diameter) bar forms, and an end-on view does get closer to fitting the central dispersion profile (and fits the h3 amplitude) without the need for a central dark mass, while adding a black hole of 2.5 × 109 M, in line with the prediction from scaling relations, allows us to fit the dispersion peak and h3 profiles. Both models, however, still fail to fit the central h4 value (overpredicting the mean velocity). The claimed large mass of the presumed black hole therefore mostly relies on the measured positive high central h4 (at high dispersion), which can be associated with broad wings in the line-of-sight velocity distribution (high-velocity stars). This emphasizes the need to go beyond medium-resolution long-slit kinematics, with e.g. high-resolution integral-field spectroscopic data. In the specific case of NGC 1277, molecular or ionized gas kinematics (if present) within the central arcsecond (or at large scale) may provide a strong discriminant between these various models. We finally briefly discuss the fact that NGC 1277 resembles a scaled-up version of e.g. NGC 4342, another nearly edge-on fast rotator with a potentially large (but not overmassive) black hole.

INTRODUCTION

A recent claim has been recently made by van den Bosch et al. (2012) that the fast-rotator galaxy NGC 1277 hosts an overmassive black hole with a mass (17 ± 3 × 109 M) quoted as larger than half the stellar bulge mass. This departs very significantly from predictions of the so-called MBH–σ relation (see e.g. Tremaine et al. 2002), or the bulge–black hole mass relation. The best-fitting model including a relatively small size black hole (108 M) with respect to its spheroidal component, and using the same mass-to-light ratio, fails to fit e.g. the stellar velocity dispersion profile within the central 10 arcsec (see their fig. 3). This emphasizes the fact that a large 17 ± 3 × 109 M black hole would influence the potential of the galaxy far out, a few hundreds of parsec from its central location. If confirmed, the existence of this overmassive black hole (relatively to the host galaxy) could either be a rare and exotic case, or would actually shed new light on the relation between the formation and evolution processes of early-type fast rotators and their central dark mass.

In this short paper, we revisit this claim by building simple dynamical models based on the multi-Gaussian expansion (MGE) technique (Emsellem, Monnet & Bacon 1994), also used in the modelling approach adopted by van den Bosch et al. (2012). The goal of the present paper is not to perform new fits to the observed data set. Here, we explore further what are the main constraints motivating the need for a very large black hole mass, and wish to examine whether other slight variations in the input assumptions may help reconcile the specific case of NGC 1277 with the above-mentioned scaling relations. We also examine the potential impact of an inner bar for the observed stellar kinematics of such a fast rotator (see e.g. Gerhard 1988), and more specifically its potential effect on the central stellar velocity dispersion. This could result in important diagnostics and in a near future help refute or confirm the claim of van den Bosch et al. (2012, hereafter vdB+12).>>
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Re: UTexas: Upgraded Hobby-Eberly Telescope Dedicated

Postby BDanielMayfield » Thu Apr 13, 2017 4:45 pm

Your killing me Art (both paternally [Texan] and maternally [Dutch]). Yeah, van is Dutch (but they're working mostly at German institutions, good for them). Nevertheless it looks like their reach exceeded their grasp and they probably got it wrong.
With all the hype they got they might have felt like a bunch of boobs.


That still ain't the 'scope's fault, dag nag it!

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Re: UTexas: Upgraded Hobby-Eberly Telescope Dedicated

Postby neufer » Thu Apr 13, 2017 8:26 pm

BDanielMayfield wrote:
Your killing me Art (both paternally [Texan] and maternally [Dutch]). Yeah, van is Dutch (but they're working mostly at German institutions, good for them). Nevertheless it looks like their reach exceeded their grasp and they probably got it wrong.

With all the hype they got they might have felt like a bunch of boobs.
That still ain't the 'scope's fault, dag nag it!

    Those Dutchmen just go for Baroque, I guess.
https://en.wikipedia.org/wiki/Peter_Paul_Rubens wrote:
<<Sir Peter Paul Rubens (28 June 1577 – 30 May 1640) was a Flemish/Netherlandish draughtsman and painter. Rubens nudes of various biblical and mythological women are especially well-known. Painted in the Baroque tradition of depicting women as soft-bodied, passive, and highly sexualized beings, his nudes emphasize the concepts of fertility, desire, physical beauty, temptation, and virtue. Rubens was quite fond of painting full-figured women, giving rise to terms like 'Rubensian' or 'Rubenesque' (sometimes 'Rubensesque').>> :arrow:
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Re: UTexas: Upgraded Hobby-Eberly Telescope Dedicated

Postby BDanielMayfield » Thu Apr 13, 2017 8:32 pm

Cute snake (among other things). We have lots of 'em in Texas. Don't mess.
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