Friday, August 26, 2011

Thursday, August 25, 2011

Do we need a Physics Barbie?

Last week we learnt that the numbers of students sitting A-level physics has increased but that the gender divide is getting worse,

This week we discover that at GCSE level, both the numbers taking science and the percent have girls have increased - with 46% of double science entrants this year being girls. The girls continue to outperform the boys, both overall, and in science (which seems to me should put pay to any ideas about intrinsic lack of science ability in girls) but yet this doesn't translate to girls taking Physics at A-level.

Imram Khan comments in the CASE reaction to the GCSE results (which he wrote, causing me to wonder what the rules are on quoting your self in an article).

"We need to encourage more girls to take the top grades they get at GCSE and translate those into science and maths A-levels."

 In related news, this week, the September 2011 Issue of Nature Chemistry celebrates women chemists in its cover - a photo mosaic of Marie Curie made up of the images of 200 women chemists (reproduced below).

A portrait of Marie Curie's face created from the photographs of around 200 women scientists.
In this volume, Michelle Francl (a Chemistry professor from Bryn Mawr College in the USA) writes a wonderful commentary: "Sex and the Citadel of Science" in which she wonders why 100 years after Marie Curie won the Nobel Prize for Chemistry so few other women have followed her to Stockholm.

 She puts forward a new and intriguing (at least to me) idea, that subtle messages from our working environment could be putting off women in science. As an example she talks about ergonomics - still general calibrated to the average size of men, for example:
"Chairs — in meeting rooms and conference venues are built to accommodate the majority of men, and the minority of women (less than 5% in fact). Most women will look — and perhaps feel — just a bit out of place, faintly childlike in an outsized chair."
Although I would argue that is true of all office spaces, many of which do not have the same gender imbalance as science.

 I was also interested to read her ideas on the use of colour as a subtle message about who belongs in science:
"It makes me wonder if one reason the science and engineering pipeline begins to leak girls at middle school is not due to some innate sex-linked lack of interest, but because that's often when 'real' lab equipment starts to be used regularly, the colours of which are drawn largely from the male-associated palette."
 This led to a silly Twitter conversation between myself, @sarahkendrew and @allinthegutter (all female astronomers) about how we only like red galaxies not blue ones, but actually I do wonder if all the beautiful images in astronomy could be responsible for a slightly higher female proportion in (some subfields) of astronomy than in physics as a whole (for which statement I should look up a reference).

Just look at all these pink galaxies from Google Images! I wonder how many female astronomers can be traced by to Halpha being commonly displayed as pink in images....?

 Being serious again though I do wonder if she has a point, Dr. Francl explains that obviously a single trivial detail like chair height, or the colour of lab equipment is not enough to put a girl off science, but she wonders about the cumulative effect of all these subtle messages, comparing it to the method of chemically separating substances by performing a procedure which slightly separates them multiple times.

 To cap all this off (and inspiring the title of my post) Athene Donald is also writing about the impacts of gender in science in THE: "Where is Physics Barbie?". The increase in Physics A-levels has been attributed by the BBC to a rise in "Geek Chic", but Dr. Donald (along with Alice Bell in her blog post "Unravelling the Politics of Geek Chic") laments that our idea of a geek is still very male (and middle class), and that we are forcing these stereotypes on our kids from a young age - partially by the choice of toys. As a mother to two young children I will gladly admit to the disquiet I feel at the very pink "girls" toys, and the very green and brown "boys" toys. I will even admit to my dismay that my 4 1/2 year old daughter is really keen to get a Princess Barbie.

Computer Scientist Barbie exists (and even blogs for UKRC), and in the 1960s apparently there was a Rocket Scientist/Astronaut Barbie, but I can say from personal experience that most of the Barbie aisle is pink, and very stereotypically girly.

Rocket Scientist Barbie
I'm currently knitting my daughters only Barbie a dress (she has a Disney Ariel Barbie which just came with a mermaid tails and bikini) which I am sorry to admit panders to her wishes and so will be very pink and twirly..... All this makes me wonder if my next project should be a Physicist outfit for the doll - and if it was how would it look. I would argue that she could in fact wear a pink frilly summer dress! Perhaps I'll just add a computer!

Anyway I'm not sure why all of this is making the online news this week, but I'm glad it is. Any discussion of the issues in my opinion is a good thing. As an MIT study showed - things only seem to improve when we're paying attention.

And I am happy to report I have an adjustable chair set at just the right height for me. A standard desk though (just too high?) and a very brown and green mens club looking coffee room to sit in. Perhaps I'll ask the department to put up some pictures of pink galaxies soon!

A Supernova in Beautiful Galaxy M101

After starting my series of beautiful galaxies with Messier 100 I was amused to discover this morning that M101 (The Pinwheel Galaxy) is in the astronomical news after a possible Type 1a Supernova was discovered in it yesterday. So following M100 I obviously have to do M101 this morning!

M101 as seen in a mosaic of Hubble Space Telescope images added to some ground based data. Credit: NASA and Robert Gendler. For more info see APOD
M101 was classified in the Hubble Atlas as an Sc galaxies with a weak bar and a partial ring around the bar before the arms emerge (SAB(rs)c). It's illustrated twice in the atlas, with the largest illustration accompanied by text which describes it as the prototype of multiple armed Sc galaxies, what we might today call a "flocculent" spiral.

 According to the "Atlas of the Messier Objects", M101 is the third largest galaxy (in angular size) in the Messier list, and is visible as an extended object even through 10x50 binoculars (presumably only from a very dark site though). It definitely seems to be a popular deep sky object for amateurs, and following the SN1a discovery the AAVSO have put out a call for their members to get observing. Some predictions suggest the supernova is still brightening and could reach 10th magnitude - only 2 magnitudes fainter than Neptune (at its brightest).

 M101 has already been an important calibrating object for the extragalactic distance ladder having had its distance measured using many of the well known methods (e.g. the Leavitt Law (Cepheids), Tip of the Red Giant Branch, the Tully-Fisher relation). The most reliable distances have ranged from 6-8 Mpc (18-24 million light years or so) making the galaxy almost twice as large as our own Milky Way.

 The addition of a Type 1a Supernova in M101 would obviously be extremely exciting as a way to further link commonly used distance indicators. SNIa are an important type of object in astronomy - they are extremely bright, and therefore observable at very large distances. Much of the evidence for the acceleration of the expansion of the universe (which indicates the need for "dark energy") comes from measurements of SN1a at very large distances which suggest that in the past the universe was expanding more slowly than it is today!

 It will be interesting to see the result of the many follow-up observations of the SN in M101 - and exciting to think they are happening (on the other side of the world of course) as I write this.

Wednesday, August 24, 2011

Multi-wavelength views of stuff

I just know I'm going to want to find this again to use in a public talk, and it's fantastic so I want to share. "The Earth and Friends in Multiple Wavelengths", by Rob Simpson (@orbitingfrog). Of course galaxies are my favourite, so I'm reproducing the image of M31 (the Andromeda galaxy) in here (from top left to bottom right, radio, microwave, infrared, optical, UV, Xray).

And I like flowers too - so here's a geranium in optical (left) and UV.

Thanks for the excellent post Rob.

Thursday, August 18, 2011

Career Progression in Academic Science from the Royal Society

I can't actually remember where I first came across the below diagram, but I keep wanting to refer to it and as finding it on the Royal Society website is not trivial (it's in a report called "The Scientific Century" from March 2010) I thought I would write a quick blog post so I could always find it.

Diagram from "The Scientific Century" by the Royal Society. Their caption reads "This diagram illustrates the transition points in typical academic scientific careers following a PhD and shows the flow of scientifically-trained people into other sectors. It is a simplified snapshot based on recent data from HEFCE, the Research Base Funders Forum  and for the Higher Education Statistics Agency's annual Destinations of Leavers from Higher Education (DLHE) survey. It also draws on Vitae's analysis of the DLHE survey. It does not show career breaks or moves back into academic science from other sectors."
I think all incoming graduate students, and graduate students thinking about getting a first postdoc should be made to spend at least 10 minutes staring at this diagram. It probably wouldn't make a difference, because I think all of  us start out our PhDs thinking we'll make the 3.5% with permanent jobs (probably also the 0.45% making Professor). And actually I think that's natural. Almost every single person starting a PhD will have been used to coming top of the class through school, and probably also has done very well at University, so is just not used to thinking of themselves as anything but the top 3.5% of a population.

 I think this diagram illustrates the numbers I already technically knew all about much better than anything else I've seen. I'd only like to add in some little people making comments about what they think of it. For example I could add a politician looking at the 79.5% of people with science PhD ending up in "Careers outside science" and say how fantastic this is that they are contributing to other sectors of the economy. I could add a Professor saying "It obviously works to select the best scientists out of the incoming pool". And I could add the postdoc approaching the transition to "permanent research staff", after having already devoted around 10 years to building up an academic career (PhD +postdoc time) and by now having realised that everyone of the other postdocs around them is equally dedicated and excellent at science as they are wondering how on Earth they persuade anyone they should be part of that 3.5% who get to make a life-long career out of it....

Curious? What if the Earth were a cube?

As I have mentioned before, as a graduate student and young postdoc I was a member of a group of Cornell affiliated astronomers who revamped the "Curious? Ask an Astronomer" site at Cornell into a sort of "proto-blog". On that site there are many answers I wrote to questions sent in to the site (154 in total over a period of about 5 years). Most of the "trouble" I get into about that period of my public engagement, centres around my answer to "What's going to happen on December 21st 2012?"  which I first wrote in January 2006 and which to date has been read over 650,000 times. But I also posted lots of other answers.

Thanks to Twitter I discovered last night that one of my old answers got picked up this week and linked into an article on the Discovery News: What if Earth were a cube? (My article: "How would the weather on Earth be different if it were a cube?" posted in December 2002). I'm always a bit worried when this happens that my previous self (9 years ago in this case) would have made some big mistake. In this case I'll say I'm still reasonably happy with what I wrote. I like the discussion of how the ocean and the atmosphere would have to be spherical even if the Earth could somehow be a cube. I think what is missing is a discussion of the fact that the Earth is so massive that it just couldn't be a cube, although I did link to another answer explaining "Why are stars and planets round?", by the wonderful educator and Saturn expert Britt Scharringhausen (now a professor at Beloit College in Wisconsin).

It was also fun to be reminded of the diagram I drew to illustrate my post:

Cubical Earth by me in 2002. 
Somewhat more impressive illustrations exist online now if you Google Image search "Cube Earth"!

Wednesday, August 17, 2011

What is Hoag's Object?

Perhaps one of the most striking looking galaxies I know of is "Hoag's Object" (seen below by the Hubble Space Telescope; NED information, Wikipedia articlelookUP information). The wikipedia article talks of it as an object which fascinates both amateur and professional astronomers.

 I am really curious to know how it might look through an amateur telescope, and I'd love to see it for myself some day (RA=15 17 14, Dec=+21 35 08 in the Serpens constellation), can help give an idea - see Hoag's Object images on Flickr found by the service.

HST Image of Hoag's Object. Credit: NASA.

Through HST as you can see the object appears to be made up of a red spheroidal core, surrounded by a blue ring of star formation (with a gap between the two). The ring shows some spiral structure. In my opinion, one of the most fun things about the object is the more distance ring galaxy which can be seen through the gap (just to the right of 12 o'clock). This to me demonstrates the sheer size of the universe. To find such a rare object behind such a rare object seems quite extraordinary. 

So why am writing about Hoag's Object today, well appearing on the arXiV this morning is a paper addressing the formation scenarios for Hoag's Object (Finkelman et al. 2011, MNRAS in press), which struck my interest so I thought I'd write about it. It puts forward a new scenario for the formation of this unusual object as well as talking about the two previously suggested models. In addition they present some new data for our consideration.

 The three models discussed are:

1. Ring formed as a collisional ring.

In this model another galaxy would have passed through the centre of Hoag's object, and what is observed is the merger remnant. The Cartwheel Galaxy is perhaps the most famous of this class of objects. It's shown below in a HST image, and illustrates the most obvious problem with interpreting Hoag's Object in this way.

Cartwheel Galaxy. Credit: HST, NASA
You can see quite clearly in the above image the culprits in the galactic collision. No such neighbours exist for Hoag's Object. In addition the ring appears to be at rest with respect to the central spheroid - which would be unlikely if the ring were collisional.

2. Ring formed through a bar instability which has since dissolved. 

 In this model at an earlier time there would have been a strong bar, and material would have flowed out along it to form the ring. The main objection to this theory appears to be the lack of evidence for any residual bar in the central spheroid. I should perhaps point out that this was a theory previously put forward by one of the co-authors of today's paper (Noah Brosch), so presumably his co-authorship on this new paper is an indication that he no longer believes this to be the best model.

3. Gas Accretion. 

This is the new theory put forward (although I should say it seems rather similar to me to one discussed by Schwiezer et al. 1987). In this model the object has a very low density HI disk which accreted at early times onto the spheroid and is only dense enough to form stars in the ring.

In fact the kinematic data does seem to suggest that Hoag's object (other than having its only visible disk light in a ring of course) is a normal disk galaxy, with the spheroidal component playing the role of a central classical bulge. At the risk of getting too technical in a blog, check out the Halpha velocity map and HI line profile below.

Ignoring the gap in the Halpha velocity map these two observations look to me basically identical to what you would expect from a normal nearly face-on disk galaxy. The classic "double horned" HI profile is usual interpreted as a coming from a rotating disk of HI with a central gap. HI (atomic hydrogen in its ground state) emits (due to hyperfine spitting of the ground state) at a single frequency of 1420 Mz (21cm) - the broadening of the line is caused by Doppler shifting of the emission (indicated along the x-axis is the velocity of the Doppler shifter HI line) and the peaks at the maximum velocity are interpreted as a pile up of HI in the flat part of a galaxy rotation curve (see global HI profiles, or galaxy rotation curves for more information on this).

HI in Hoag's Object from Schwiezer et al. 1987

The Halpha velocity map is showing a similar thing. Halpha is a spectral line emitted by excited hydrogen. Again this emits at a single frequency (656.28 nm), which is shifted due to the Doppler effect. The map shows the velocity of this line colour coded such that red indicates a greater velocity than the mean for the galaxy and blue a smaller. This is again interpreted as a rotating disk of hydrogen with the upper left moving away from use and the lower right towards us. The velocities are very consistent with what's seen in the HI profile, suggesting the HI is indeed coming from the ring.
Halpha velocity field in Hoag's Object from Finkelman et al. 2011

 What is needed to complete this picture is a HI map of Hoag's Object. I think this could be fairly easilly done with the EVLA, and I will be interested to see it when it is.

Solar Observing in Eastney

On Sunday I took one of the ICG Gallieoscopes to the Arts Cafe at Eastney Community Centre who are currently hosting a Space Themed Exhibit: "Journey to the Edge Of Space". As part of this they organized a Family Space Day on Sunday, and I agrred to go along to provide some public solar observing.

Picture of the Galileoscope set up for Solar Observing
It was a fairly quiet event in the end, and a day with patchy cloud, but I was able to show a few 10s of people the Sun through the telescope. Not helping the educational content from this was the quiet Sun. Absolutely no sun spots were visible, making the Sun appear as smooth white circle through the solar filter (I knew this in advance because I had looked it up on - still disappointing). It was almost more interesting when the patchy clouds went across the disk.

ICG news article. 

Monday, August 15, 2011

Zui Wanzheng 3D Yuzhou Tu

Thanks to the Chinese side of my family I found out that the story about the release of the 2MASS Redshift Survey ("The Most Complete Map of the 3D Universe") even appeared in the Chinese newspaper "World Journal".

The headline in black reads "Zuì wánzhěng 3D yǔzhòu tú" which is literally translated to "Most complete 3D universe map".

Friday, August 12, 2011

Leverhulme Trust Article about Galaxy Zoo Bars

Over on the Leverhulme Trust Awards in Focus section this month is an article I wrote for them about the progress I've made on the research project they fund me for - which is to study the impact of bars on disk galaxies using Galaxy Zoo.

Thursday, August 11, 2011

What Types of Galaxies are in BOSS?

Over on the SDSS3 blog is a post about my recently accepted paper looking at the types of galaxies which are being observed in BOSS.

Copied below:

A critical question for the SDSS-III BOSS is what kinds of galaxies are they observing. In a recent paper by Masters et al., SDSS-III scientists used additional, higher resolution data from the Hubble Space Telescope (HST) to answer this questions.
In SDSS images, BOSS galaxies, which are on average about 6 billion light years away, just looks like fuzzy red blobs. The goal of BOSS is to observe 1.5 million of them over 30% of the sky in order to map the large scale structure in great detail. For this study, they took a look at a tiny subset of 230 of them which have deeper HST images (which were taken as part of the COSMOS project – the largest area HST survey every yet done).
The study found that 75% of BOSS galaxies are massive ellipticals, but that a surprisingly high fraction (20%) of these are split into multiple components in the HST images. The remaining 25% of BOSS galaxies are massive spirals.
The image below shows an example of one of the spirals and one of the ellipticals shown in both the SDSS and HST image.
As well as the paper, you can look at a poster about this work which was presented both at the AAS in Boston in May, and also at the recent Galaxy Formation conference in Durham
Finally if you want to browse all the images yourself they are available at

Talking about the Universe on Radio New Zealand

Yesterday I talked with Bryan Crump from Radio New Zealand Nights about the 2MASS Redshift Survey. You can listen to the segment online, or download MP3.

Screenshot of 2MRS on the Radio New Zealand Website.

 Lucas also submitted the scientific paper to the Astrophysical Journal Supplement Series and released it to the arXiV last week.

Thursday, August 4, 2011